Proto-Germanic (often abbreviated PGmc.), Common Germanic or Ur-Germanic, as it is sometimes known, is the unattested, reconstructed proto-language of all the Germanic languages, including English. By definition, Proto-Germanic is the stage of the language constituting the most recent common ancestor of the attested Germanic languages. Proto-Germanic is itself descended from Proto-Indo-European (PIE).
Although Proto-Germanic was reconstructed as a node in the tree model of language development, its main innovations must have followed a logical and therefore a chronological sequence, leading to the hypothesis that, over its estimated life of nearly one thousand years, roughly 500 BC to 500,[clarification needed] it underwent phases of development. Each phase but the last featured some, but not all, of the common innovations. Moreover, the final phases, and perhaps the initial, were already divided into dialects, some of which would lead to distinct languages, which began at the point of mutual unintelligibility. That point is often difficult to determine, and as such there may have never been any uniform Proto-Germanic.
The Proto-Germanic language is not directly attested by any surviving texts but has been reconstructed using the comparative method. However, a few surviving inscriptions in a runic script from Scandinavia, the Vimose inscriptions, dated to c. 200, may represent a stage of Proto-Norse or, according to Bernard Comrie, late Common Germanic immediately following the "Proto-Germanic" stage.
Evolution of Proto-Germanic (PGmc) 
The evolution of Proto-Germanic began with the separation of a common way of speech among some geographically proximate speakers of a prior language and ended with the dispersion of the proto-language speakers into distinct populations practicing their own speech habits. Between those two points many sound changes occurred.
Theories of phylogeny 
Solutions to the phylogeny problem 
Phylogeny applied to historical linguistics is the evolutionary descent of languages. The phylogeny problem is the question of what specific tree, in the tree model of language evolution, best explains the paths of descent of all the members of a language family from a Common, or Proto language at the root of the tree to the attested languages at the leaves of the tree. The Germanic languages form a tree with Proto-Germanic at its root. This tree is a branch of the Indo-European tree with Proto-Indo-European at its root. Due to borrowing of lexical items from contact languages, the position of the Germanic branch within Indo-European is more ambiguous than the positions of the other branches of Indo-European. Over the life of historical linguistics, various solutions have been proposed, none certain, and all debatable.
To the evolutionary history of a language family, a genetic "tree model" is considered appropriate only if communities do not remain in effective contact as their languages diverge. Early IE was computed to have featured limited contact between distinct lineages, while only the Germanic subfamily exhibited a less treelike behaviour as it acquired some characteristics from neighbours early in its evolution rather than from its direct ancestors. The internal diversification of especially West Germanic is cited to have been radically non-treelike.
Proto-Germanic is generally agreed to have begun about 500 BC. The hypothetical development between the end of Proto-Indo-European and 500 BC is termed Pre-Proto-Germanic. Whether it is to be included under a wider meaning of Proto-Germanic is a matter of usage.
W. P. Lehmann considered that Jacob Grimm's "First Germanic Sound Shift", or Grimm's Law and Verner's Law, which pertained mainly to consonants and were considered for a good many decades to have generated Proto-Germanic, were pre-Proto-Germanic, and that the "upper boundary" was the fixing of the accent, or stress, on the root syllable of a word, typically the first. Proto-Indo-European had featured a moveable pitch accent comprising "an alternation of high and low tones" as well as stress of position determined by a set of rules based on the lengths of the word's syllables.
The fixation of the stress led to sound changes in unstressed syllables. For Lehmann, the "lower boundary" was the dropping of final -a or -e in unstressed syllables; for example, post-PIE *woyd-á > Gothic wait, "knows." Antonsen agreed with Lehmann about the upper boundary but later found runic evidence that the -a was not dropped: ékwakraz … wraita, "I wakraz … wrote (this)." He says: "We must therefore search for a new lower boundary for Proto-Germanic."
His own scheme divides Proto-Germanic into an early and a late. The early includes the stress fixation and resulting "spontaneous vowel-shifts" while to define the late he lists ten complex rules governing changes of both vowels and consonants.
By 250 BC, Proto-Germanic had branched into five groups of Germanic (two each in the West and the North, and one in the East).
Archaeological contributions 
||This article is incomplete. (January 2012)|
It is possible that Indo-European speakers arrived on the plains of southern Sweden and Jutland, the center of the Urheimat[clarification needed] or "original home" of the Germanic peoples, prior to the Nordic Bronze Age, which began about 4500 years ago. This is the only area where no pre-Germanic place names have been found. The region was certainly populated before then; the lack of names must indicate an Indo-European settlement so ancient and dense that the previously assigned names were completely replaced. If archaeological horizons are at all indicative of shared language (not a straightforward assumption), the Indo-European speakers are to be identified with the much more widely ranged Cord-impressed ware or Battle-axe culture and possibly also with the preceding Funnel-necked beaker culture or the Pitted Ware culture developing towards the end of the Neolithic culture of Western Europe.
Proto-Germanic then evolved from the Indo-European spoken in the Urheimat region.[clarification needed] The succession of archaeological horizons suggests that before their language differentiated into the individual Germanic branches the Proto-Germanic speakers lived in southern Scandinavia and along the coast from the Netherlands in the west to the Vistula in the east around 750 BC.
Phonological stages from Proto-Indo-European through the end of Proto-Germanic 
The following changes are known or presumed to have occurred in the history of Proto-Germanic in the wider sense from the end of Proto-Indo-European up to the point that Proto-Germanic began to break into mutually unintelligible dialects. The changes are roughly in chronological order, with changes that operate on the outcome of earlier ones appearing later in the list. The stages distinguished and the changes associated with each stage rely heavily on Ringe 2006, Chapter 3, "The development of Proto-Germanic". Ringe in turn is summarizing standard concepts and terminology.
Pre-Proto-Germanic (Pre-PGmc) 
This stage began with the separation of a distinct speech, perhaps while still forming part of the Proto-Indo-European dialect continuum. It contained many innovations that were shared with other Indo-European branches to various degrees, probably through areal contacts, and mutual intelligibility with other dialects would have remained for some time. It was nevertheless on its own path, whether dialect or language.
|Merging of PIE "palatal" and "velar" plosives (Germanic is therefore a centum language):
|Epenthesis of /u/ before the syllabic sonorants:
|An epenthetic /s/ was inserted already in PIE after dental consonants when followed by a suffix beginning with a dental.
|Geminate consonants are shortened after a consonant or a long vowel — *káyd-tis "act of calling" (pronounced *káydstis) > *káyssis > *káysis > *haisiz "command"|
|Word-final long vowels are lengthened to "overlong" vowels — *séh₁mō "seeds" > *séh₁mô > *sēmô|
|Loss of laryngeals, phonemicising the allophones of /e/:
|Cowgill's law: /h₃/ (and possibly /h₂/) is strengthened to /g/ between a sonorant and /w/ — *n̥h₃mé "us two" > *n̥h₃wé > *ungwé > *unk|
|Vocalisation of remaining laryngeals: /H/ > /ə/ — *ph₂tḗr "father" > *pətḗr > *fadēr; *sámh₂dʰos "sand" > *sámədʰos > *samdaz|
|Velars are labialised by following /w/: *éḱwos "horse" > *ékwos > *ékʷos > *ehwaz|
|Labiovelars are delabialised next to /u/ (or /un/) and before /t/ — *gʷʰénti- ~ *gʷʰn̥tí- "killing" > *gʷʰúntis > *gʰúntis > *gunþiz "battle"
Early Proto-Germanic 
This stage began its evolution as a form of centum PIE that had lost its laryngeals and had five long and six short vowels, as well as one or two overlong vowels. The consonant system was still that of PIE minus palatovelars and laryngeals, but the loss of syllabic resonants already made the language markedly different from PIE proper. Mutual intelligibility might have still existed, but strained, and this period marked the definitive break of Germanic from the other Indo-European languages and the beginning of Germanic proper, containing most of the sound changes that are now held to define this branch distinctively. This stage contained various consonant and vowel shifts, the loss of contrastive accent, and the beginnings of the reduction of unstressed syllables as a result.
|Loss of word-final non-high short vowels /e/, /a/, /o/ — *wóyde "(s)he knows" > *wóyd > *wait
|Grimm's law: Chain shift of the three series of plosives. Note that voiced plosives had already been devoiced before a voiceless obstruent prior to this stage. Labiovelars were delabialised before /t/.
|Verner's law: voiceless fricatives are voiced, allophonically at first, when preceded by an unaccented syllable:
|All words become stressed on their first syllable. The PIE contrastive accent is lost, phonemicising the voicing distinction created by Verner's law.|
|Word-initial /gʷ/ > /b/ — *gʷʰédʰyeti "(s)he is asking for" > *gʷédyedi > *bédyedi > *bidiþi "(s)he asks, (s)he prays" (with -þ- by analogy)|
|Assimilation of sonorants:
|Unstressed /owo/ > /oː/ — *-owos "thematic 1st du." > *-ōz|
|Unstressed /ew/ > /ow/ before a consonant or word-finally — *-ews "u-stem gen. sg." > *-owz > *-auz|
|Unstressed /e/ > /i/ except before /r/ — *-éteh₂ "abstract noun suffix" > *-eþā > *-iþā > *-iþō
|Unstressed /ji/ > /i/ — *légʰyeti "(s)he is lying down" ~ *légʰyonti "they are lying down" > *legyidi ~ *legyondi > *legidi ~ *legyondi > *ligiþi ~ *ligjanþi (with -þ- by analogy)
|Merging of non-high back vowels:
Late Proto-Germanic 
By this stage, Germanic had emerged as a distinctive branch and had undergone many of the sound changes that would make its later descendants recognisable as Germanic languages. It had shifted its consonant inventory from a system rich in plosives to one containing primarily fricatives, had lost the PIE mobile pitch accent in favour of a predictable stress accent, and had merged two of its vowels. The stress accent had also begun to cause the erosion of unstressed syllables already, which would continue in its descendants up to the present day. This final stage of the language included the remaining development until the breakup into dialects, and most notably featured the appearance of nasal vowels and the first beginning of umlaut, another characteristic Germanic feature.
|Word-final /m/ > /n/ — *tóm "that, acc. masc." > *þam > *þan "then"; *-om "a-stem acc. sg." > *-am > *-an > *-ą|
|/m/ > /n/ before dental consonants — *ḱm̥tóm "hundred" > *humdan > *hundan > *hundą; *déḱm̥d "ten" > *tehumt > *tehunt > *tehun|
|Word-final /n/ is lost after unstressed syllables, and the preceding vowel is nasalised — *-om "a-stem acc. sg." > *-am > *-an > *-ą; *-eh₂m > *-ān > *-ą̄ > *-ǭ; *-oHom "genitive plural" > *-ân > *-ą̂ > *-ǫ̂|
|Nasal /ẽː/ is lowered to /ɑ̃ː/ — *dʰédʰeh₁m "I was putting" > *dedēn > *dedę̄ > *dedą̄ > *dedǭ|
|Elimination of /ə/:
|Loss of /t/ after unstressed syllables — *déḱm̥d "ten" > *tehunt > *tehun; *bʰéroyd "(s)he would carry, subj." > *berayt > *berai; *mélid ~ *mélit- "honey" > *melit ~ *melid- > *meli ~ *melid- > *mili ~ *milid-|
|/ɣʷ/ > /w/, sometimes /ɣ/ — *snóygʷʰos "snow" > *snaygʷaz > *snaiwaz; *kʷekʷléh₂ "wheels (collective)" > *hʷegʷlā > *hʷewlā > *hweulō|
|i-mutation: /e/ > /i/ when followed by /i/ or /j/ in the same or next syllable — *bʰéreti "(s)he is carrying" > *beridi > *biridi; *médʰyos "middle" > *medyaz > *midjaz; *néwios "new" > *newyaz > *niwjaz
|/e/ > /i/ when followed by a syllable-final nasal — *en "in" > *in; *séngʷʰeti "(s)he chants" > *sengʷidi > *singwidi "(s)he sings"
|Long a is raised:
|/j/ is lost between vowels except after /i/ and /w/ (but it is lost after syllabic /u/). The two vowels that come to stand in hiatus then contract to long vowels or diphthongs — *-oyh₁m̥ "thematic optative 1sg sg." > *-oyum > *-ayų > *-aų; *áyeri "in the morning" > *ayiri > *airi "early"
|/n/ is lost before /x/, causing compensatory lengthening and nasalisation of the preceding vowel — *ḱónketi "(s)he hangs" > *hanhidi (phonetically [ˈxɑ̃ːxiði])|
Lexical evidence in other language varieties 
Loans from adjoining Indo-European groups 
Loans into Proto-Germanic from other Indo-European languages can be relatively dated by how well they conform to Germanic sound laws. Since the dates of borrowings and sound laws are not precisely known, using the loans for absolute, or calendar, chronology would be impossible.
Most loans from Celtic appear to have been made before or during the Germanic Sound Shift. For instance, one specimen *rīks 'ruler' was borrowed from Celtic *rīxs 'king' (stem *rīg-), with g → k. It is clearly not native because PIE *ē → ī is not typical of Germanic but is a feature of Celtic languages. Another is *walhaz "foreigner; Celt" from the Celtic tribal name Volcae with k → h and o → a. Other likely Celtic loans include *ambahtaz 'servant', *brunjǭ 'mailshirt', *gīslaz 'hostage', *īsarną 'iron', *lēkijaz 'healer', *laudą 'lead', *Rīnaz 'Rhine', and *tūnaz, tūną 'fortified enclosure'. These loans would likely have been borrowed during the Celtic Hallstatt and early La Tène cultures when the Celts dominated central Europe, although the period spanned several centuries.
From East Iranian have come *hanapiz 'hemp' (cf. Persian kanab), *humalaz, humalǭ 'hops' (cf. Ossetian xumællæg), *keppǭ ~ skēpą 'sheep' (cf. Pers čapiš 'yearling kid'), *kurtilaz 'tunic' (cf. Osset kwəræt 'shirt'), *kutą 'cottage' (cf. Pers kad 'house'), *paidō 'cloak', *paþaz 'path' (cf. Avestan pantā, g. pathō), and *wurstwa 'work' (cf. Av vərəštuua). These words could have been transmitted directly by the Scythians from the Ukraine plain, groups of whom entered Central Europe via the Danube, and created the Vekerzug Culture in the Carpathian Basin (6th-5th centuries BC), or by later contact with Sarmatians, who followed the same route. Unsure is *marhaz 'horse', which was either borrowed directly from Scytho-Sarmatian or through Celtic mediation.
Loans into non-Germanic languages 
In some non-Germanic languages spoken in areas adjacent to Germanic speaking areas, there are loanwords believed to have been borrowed from Proto-Germanic. Some of which include PGmc *druhtinaz 'warlord' (cf. Finnish ruhtinas), *hrengaz (later *hringaz) 'ring' (cf. Finn rengas, Estonian rõngas), *kuningaz 'king' (cf. Finn kuningas), *lambaz 'lamb' (cf. Finn lammas), *lunaz 'ransom' (cf. Finn lunnas), *markijaną 'to spot, catch sight of' (cf. Est märk(ama)), *rīkiją 'realm, empire' (cf. Est riik 'state, country'), *skappijǭ 'cupboard, shelf' (cf. Finn kaappi 'chest of drawers', Est kapp), *skelduz 'shield' (cf. Est silt 'tag, token' ), *werþą 'worth' (cf. Est väärt).
Non-Indo-European substrate elements 
The term substrate with reference to Proto-Germanic refers to lexical and phonological items that do not appear to be explained by Indo-European etymological principles. The substrate theory postulates that these elements came from a prior population that remained among the Indo-Europeans and was sufficiently influential to transmit some elements of its own language. The theory of a non-Indo-European substrate was first proposed by Sigmund Feist, who estimated that about 1/3 of the Proto-Germanic lexical items came from the substrate.
However, research in Germanic etymology continues and as more and more plausible explanations for Germanic words whose origins were previously unclear or controversial are being proposed, and which explain those words in terms of reconstructed Indo-European words and morphology, the proportion of Germanic words without any plausible etymological explanation decreases. Estimates of that proportion are typically outdated or inflated as many proposals were unknown to scholars compiling lists of unexplained Germanic words.
The following conventions are used in this article for transcribing Proto-Germanic forms:
- Voiced obstruents appear as b, d, g; this does not imply any particular analysis of the underlying phonemes as plosives /b/, /d/, /ɡ/ or fricatives /β/, /ð/, /ɣ/. In other literature, they may be written as graphemes with a bar to produce ƀ, đ and ǥ.
- Unvoiced fricatives appear as f, þ, h (perhaps /ɸ/, /θ/, /x/). /x/ may have become /h/ in certain positions at a later stage of Proto-Germanic itself. Similarly for /xʷ/, which later became /hʷ/ or /ʍ/ in some environments.
- Labiovelars appear as kw, hw, gw; this does not imply any particular analysis as single sounds (e.g. /kʷ/, /xʷ/, /ɡʷ/) or clusters (e.g. /kw/, /xw/, /ɡw/).
- The "yod" sound appears as j /j/. Note that the normal convention for representing this sound in Proto-Indo-European is y; the use of j does not imply any actual change in the pronunciation of the sound.
- Long vowels are denoted with a macron over the letter, e.g. ō. When a distinction is necessary, /ɛː/ and /eː/ are transcribed as ē¹ and ē² respectively. ē¹ is sometimes transcribed as æ or ǣ instead, but this is not followed here.
- Overlong vowels appear with circumflexes, e.g. ô. In other literature they are often denoted by a doubled macron.
- Nasal vowels are written here with an ogonek, following Don Ringe's usage, e.g. ǫ̂ /õːː/. Most commonly in literature, they are denoted simply by a following n. However, this can cause confusion between a word-final nasal vowel and a word-final regular vowel followed by /n/; a distinction which was phonemic. Tildes (ã, ĩ, ũ...) are also used in some sources.
- Diphthongs appear as ai, au, eu, iu, ōi, ōu and perhaps ēi, ēu. However, when immediately followed by the corresponding semivowel, they appear as ajj, aww, eww, iww. u is written as w when between a vowel and j. This convention is based on the usage in Ringe 2006.
- Long vowels followed by a non-high vowel were separate syllables and are written as such here, except for ī, which is written ij in that case.
The table below lists the consonantal phonemes of Proto-Germanic classified by reconstructed pronunciation. The slashes around the phonemes are omitted for clarity. If two phonemes appear in the same box, the first of each pair is voiceless, the second is voiced. Phones written in parentheses represent allophones and are not independent phonemes. For descriptions of the sounds and definitions of the terms, follow the links on the headings.
|Plosive||p b||t d||k ɡ||kʷ ɡʷ|
|Fricative||ɸ (β)||θ (ð)||s z||x (ɣ)||xʷ|
- [ŋ] was an allophone of /n/ before velar obstruents.
- [ŋʷ] was an allophone of /n/ before labial-velar obstruents.
- [β], [ð] and [ɣ] were allophones of /b/, /d/ and /ɡ/ in certain positions (see below).
- The phoneme written as f was certainly still realised as a bilabial fricative (/ɸ/) in Proto-Germanic. This can be deduced from the fact that in Gothic, word-final b devoices to f, and also from Old Norse spellings such as aptr [ɑɸtr], where the letter p rather than the more usual f was used to denote the bilabial realisation before /t/.
Grimm's and Verner's law 
Grimm's law as applied to pre-proto-Germanic is a chain shift of the original Indo-European plosives. Verner's Law addresses a category of exceptions to Grimm's Law, in which a voiced fricative appears where Grimm's Law predicts a voiceless fricative. The discrepancy is conditioned by the placement of the original Indo-European word accent.
|Labiovelar reduction (near u)||Grimm's law: Voiceless to fricative||Grimm's law: Voiced to plosive||Grimm's law: Aspirated to voiced||Verner's law||Labiovelar dissolution|
|labials||p > ɸ||b > p||bʱ > b, β||ɸ > b, β|
|dentals||t > θ||d > t||dʱ > d, ð||θ > d, ð|
|velars||k > x||ɡ > k||ɡʱ > ɡ, ɣ||x > ɡ, ɣ|
|labiovelars||kʷ > k
ɡʷ > ɡ
ɡʷʱ > ɡʱ
|kʷ > xʷ||ɡʷ > kʷ||ɡʷʱ > ɡʷ, ɣʷ||xʷ > ɡʷ, ɣʷ||ɡʷ > b
ɣʷ > w, ɣ
p, t, and k did not undergo Grimm's law after a fricative (such as s) or other plosives; for example, where Latin (with the original t) has stella "star" and octo "eight", Middle Dutch has ster and acht (with unshifted t). This original t merged with the shifted t from the voiced consonant; that is, most of the instances of /t/ came from either the original /t/ or the shifted /t/.
"Grimm's and Verner's Laws … together form the First Germanic Consonant Shift. A second, and chronologically later Second Germanic Consonant Shift … affected only Proto-Germanic voiceless stops … and split Germanic into two sets of dialects, Low German in the north … and High German further south ...."
Verner's law follows Grimm's law in time, and states that unvoiced fricatives: /s/, /ɸ/, /θ/, /x/ are voiced when preceded by an unaccented syllable. The accent at the time of the change was the one inherited from Proto-Indo-European, and was still free and could occur on any syllable. For example, PIE *bhrátēr > PGmc. *brōþēr "brother" but PIE *mātér > PGmc. *mōdēr "mother." The voicing of some /s/ according to Verner's Law produced /z/, a new phoneme. Following Grimm's and Verner's law, Proto-Germanic lost its inherited contrastive accent, and all words became stressed on their root syllable. This was usually the first syllable unless a prefix was attached.
As a result of the loss of contrastive accent, the conditioning environment for the original consonant alternations created by Verner's law was lost. As a result, since the original cause of the alternation was no longer obvious to native speakers, significant levelling occurred throughout the Germanic period as well as in the later daughter languages. The alternations became less phonetic and increasingly grammatical in nature, leading to the phenomenon known as Grammatischer Wechsel. Already in Proto-Germanic, most alternations in nouns were levelled in one direction or the other, although some were preserved, only to be levelled later in the daughters (but differently in each one). Alternations in noun and verb endings were also levelled, usually in favour of the voiced alternants in nouns, but a split remained in verbs where unsuffixed (strong) verbs received the voiced alternants while suffixed (weak) verbs had the voiceless alternants. Alternation between the present and past of strong verbs remained common and was not levelled in Proto-Germanic, and survives up to the present day in some Germanic languages.
Sometimes the shift produced consonants that were pronounced differently (allophones) depending on the context of the original. With regard to original /k/ or /kʷ/ Trask says:
"The resulting /x/ or /xʷ/ were reduced to /h/ and /hʷ/ in word-initial position."
Many of the phonemes listed in the table represent can appear lengthened or prolonged under some circumstances, appearing in some daughter languages as geminated graphemes. The phenomenon is therefore termed gemination. Kraehenmann says:
"Then, Proto-Germanic already had long consonants … but they contrasted with short ones only word-medially. Moreover, they were not very frequent and occurred only intervocally almost exclusively after short vowels."
The phonemes /b/, /d/, /ɡ/ and /ɡʷ/ were stops in some environments and fricatives in others. The pattern of allophony is not completely clear, but generally agrees with the patterns of voiced obstruent allophones in languages such as Spanish. The fricatives merged with the fricatives of Verner's Law (see above). Older accounts tended to suggest that the sounds were originally fricatives and later "hardened" into stops in some circumstances. However, Ringe notes that this belief was largely due to theory-internal considerations of older phonological theories, and in modern theories it is equally possible that the allophony was present from the beginning.
Each of the three phonemes /b/, /d/, and /ɡ/ had a different pattern of allophony from each of the others, but in general stops occurred in "strong" positions (word-initial and in clusters) while fricatives occurred in "weak" positions (post-vocalic). More specifically:
- Word-initial /b/ and /d/ were stops [b] and [d].
- A good deal of evidence, however, indicates that word-initial /ɡ/ was [ɣ], subsequently developing to [g] in a number of languages. This is clearest from developments in Anglo-Frisian and other Ingvaeonic languages. Modern Dutch still preserves the sound of [ɣ] in this position.
- Plosives appeared after homorganic nasal consonants: [mb], [nd], [ŋɡ], [ŋʷɡʷ]. This was the only place where a voiced labiovelar [ɡʷ] could still occur.
- Gemination produced [bb], [dd], [ɡɡ]. This rule continued to apply at least into the early West Germanic languages, since the West Germanic gemination produced geminated plosives from earlier voiced fricatives.
- /d/ was [d] after l or z. Evidence for /d/ after /r/ is conflicting: it appears as a plosive in Gothic waurd "word" (not *waurþ, with devoicing), but as a fricative in Old Norse orð. /d/ hardened to [d] in all positions in the West Germanic languages.
- In other positions, fricatives occurred: Singly after vowels and diphthongs, and after non-nasal consonants in the case of /b/ and /g/.
Numerous additional changes affected the labiovelars.
- Even before the operation of Grimm's law, they were reduced to plain velars next to /u/. This appears to be a sound law that was inherited from PIE and continued to operate as a surface filter, i.e. if a sound change generated a new environment in which a labiovelar occurred near a /u/, it was immediately converted to a plain velar. This caused certain alternations in verb paradigms, such as *singwaną [siŋɡʷɑnɑ̃] ('to sing') versus *sungun [suŋɡun] ('they sang'). Apparently, this delabialization also occurred after /un/, showing that the language possessed a labial allophone [ŋʷ] as well. In this case the entire clusters [uŋʷxʷ], [uŋʷkʷ] and [uŋʷgʷ] are delabialized to [uŋx], [uŋk] and [uŋg].
- After the operation of Verner's law, various changes conspired to almost completely eliminate voiced labiovelars. Initially, [ɡʷ] became [b], e.g. PIE *gʷʱédʱyeti > PGmc. bidiþi "(s)he asks for". The fricative variant [ɣʷ] (which occurred in most non-initial environments) usually became [w], but sometimes instead turned into [ɣ]. The only environment in which a voiced labiovelar remained was after a nasal, e.g. in *singwaną [siŋɡʷɑnɑ̃] "to sing". These various changes often led to complex alternations, e.g. *sehwaną [sexʷɑnɑ̃] ('to see'), *sēgun [sɛːɣun] ('they saw', indicative), *sēwīn [sɛːwiːn] ('they saw', subjunctive), which were reanalysed and regularised differently in the various daughter languages.
Proto-Germanic had four short vowels five or six long vowels, and at least one "overlong" or "trimoric" vowel. The exact phonetic quality of the vowels is uncertain.
- /e/ could not occur in unstressed syllables except before /r/, where it may have been lowered to /ɑ/ already in late Proto-Germanic times.
- All nasal vowels except /ɑ̃ː/ and /ũː/ occurred word-finally. The long nasal vowels /ɑ̃ː/, /ĩː/ and /ũː/ occurred before /x/, and derived from earlier short vowels followed by /nx/.
PIE ə a o merged into PGmc a; PIE ā ō merged into PGmc ō. At the time of the merger, the vowels probably were [ɑ] and [ɑː], or perhaps [ɒ] and [ɒː]. Their timbres then differentiated by raising (and perhaps rounding) the long vowel to [ɔː]. It is known that the raising of ā to ō can not have occurred earlier than the earliest contact between Proto-Germanic speakers and the Romans. This can be verified by the fact that Latin Rōmānī later emerges in Gothic as Rumoneis (that is, Rūmōnīs). It is explained by Ringe that at the time of borrowing, the vowel matching closest in sound to Latin ā was a Proto-Germanic ā-like vowel (which later became ō). And since Proto-Germanic therefore lacked a mid(-high) back vowel, the closest equivalent of Latin ō was Proto-Germanic ū: Rōmānī > *Rūmānīz > *Rūmōnīz > Gothic Rumoneis.
A new ā was formed following the shift from ā to ō when intervocalic /j/ was lost in -aja- sequences. It was a rare phoneme, and occurred only in a handful of words, the most notable being the verbs of the third weak class. The agent noun suffix *-ārijaz (Modern English -er) was likely borrowed from Latin around or shortly after this time.
The following diphthongs are known to have existed in Proto-Germanic:
- Short: /ɑu/, /ɑi/, /eu/, /iu/
- Long: /ɔːu/, /ɔːi/, (possibly /ɛːu/, /ɛːi/)
Note the change /e/ > /i/ before /i/ or /j/ in the same or following syllable. This removed /ei/ (which became /iː/) but created /iu/ from earlier /eu/.
Diphthongs in Proto-Germanic can also be analysed as sequences of a vowel plus an approximant, as was the case in Proto-Indo-European. This explains why /j/ was not lost in *niwjaz ("new"); the second element of the diphthong iu was still underlyingly a consonant and therefore the conditioning environment for the loss was not met. This is also confirmed by the fact that later in the West Germanic gemination, -wj- is geminated to -wwj- in parallel with the other consonants (except /r/).
Overlong vowels 
Proto-Germanic had two overlong or trimoraic long vowels ô [ɔːː] and ê [ɛːː], the latter mainly in adverbs (cf. *hwadrê "whereto, whither"). None of the documented languages still include such vowels. Their reconstruction is due to the comparative method, particularly as a way of explaining an otherwise unpredictable two-way split of reconstructed long ō in final syllables, which unexpectedly remained long in some morphemes but shows normal shortening in others. (See below.)
Trimoraic vowels generally occurred at morpheme boundaries where a bimoraic long vowel and a short vowel in hiatus contracted, especially after the loss of an intervening laryngeal (-VHV-). One example, without a laryngeal, includes the class II weak verbs (ō-stems) where a -j- was lost between vowels, so that -ōja → ōa → ô (cf. *salbōjaną → *salbôną → Gothic salbōn "to anoint"). However, the majority occurred in word-final syllables (inflectional endings) probably because in this position the vowel could not be resyllabified. Additionally, Germanic, like Balto-Slavic, lengthened bimoraic long vowels in absolute final position, perhaps to better conform to a word's prosodic template; e.g., PGmc *arô "eagle" ← PIE *h₃érō just as Lith akmuő "stone", OSl kamy ← *aḱmō̃ ← PIE *h₂éḱmō). Contrast:
- contraction after loss of laryngeal: gen.pl. *wulfǫ̂ "wolves'" ← *wulfôn ← pre-Gmc *wúlpōom ← PIE *wĺ̥kʷoHom; ō-stem nom.pl. *-ôz ← pre-Gmc *-āas ← PIE *-eh₂es.
- contraction of short vowels: a-stem nom.pl. *wulfôz "wolves" ← PIE *wĺ̥kʷoes.
But vowels that were lengthened by laryngeals did not become overlong. Compare:
- ō-stem nom.sg. *-ō ← *-ā ← PIE *-eh₂;
- ō-stem acc.sg. *-ǭ ← *-ān ← *-ām (by Stang's law) ← PIE *-eh₂m;
- ō-stem acc.pl. *-ōz ← *-āz ← *-ās (by Stang's law) ← PIE *-eh₂ns;
Trimoraic vowels are distinguished from bimoraic vowels by their outcomes in attested Germanic languages: word-final trimoraic vowels remained long vowels while bimoraic vowels developed into short vowels. Older theories about the phenomenon claimed that long and overlong vowels were both long but differed in tone, i.e., ô and ê had a "circumflex" (rise-fall-rise) tone while ō and ē had an "acute" (rising) tone, much like the tones of modern Scandinavian languages, Baltic, and Ancient Greek, and asserted that this distinction was inherited from PIE. However, this view was abandoned since languages do not combine distinctive intonations on unstressed syllables with contrastive stress and vowel length. Modern theories have reinterpreted overlong vowels as having superheavy syllable weight (three moras) and therefore greater length than ordinary long vowels.
By the end of the Proto-Germanic period, word-final long vowels were shortened to short vowels. Following that, overlong vowels were shortened to regular long vowels in all positions, merging with originally long vowels except word-finally (because of the earlier shortening), so that they remained distinct in that position. This was a late dialectal development, because the end result was not the same in all Germanic languages: word-final ē shortened to a in East and West Germanic but to i in Old Norse, and word-final ō shortened to a in Gothic but to o (probably [o]) in early North and West Germanic, with a later raising to u (the 6th century Salic law still has maltho in late Frankish).
The shortened overlong vowels in final position developed as regular long vowels from that point on, including the lowering of ē to ā in North and West Germanic. The monophthongization of unstressed au in Northwest Germanic produced a phoneme which merged with this new word-final long ō, while the monophthongization of unstressed ai produced a new ē which did not merge with original ē, but rather with ē2, as it was not lowered to ā. This split, combined with the asymmetric development in West Germanic, with ē lowering but ō raising, points to an early difference in the articulation height of the two vowels that was not present in North Germanic. It could be seen as evidence that the lowering of ē to ā began in West Germanic at a time when final vowels were still long, and spread to North Germanic through the late Germanic dialect continuum, but only reaching the latter after the vowels had already been shortened.
ē¹ and ē² 
ē² is uncertain as a phoneme, and only reconstructed from a small number of words; it is posited by the comparative method because whereas all provable instances of inherited (PIE) *ē (PGmc. *ē¹) are distributed in Gothic as ē and the other Germanic languages as *ā, all the Germanic languages agree on some occasions of ē (e.g., Got./OE/ON hēr "here" ← PGmc. *hē²r). Gothic makes no orthographic and therefore presumably no phonetic distinction between ē¹ and ē², but the existence of two Proto-Germanic long e-like phonemes is supported by the existence of two e-like Elder Futhark runes, Ehwaz and Eihwaz.
Krahe treats ē² (secondary ē) as identical with ī. It probably continues PIE ēi, and it may have been in the process of transition from a diphthong to a long simple vowel in the Proto-Germanic period. Lehmann lists the following origins for ē²:
- ēi: Old High German fiara, fera "ham", Goth fera "side, flank" ← PGmc *fē²rō ← *pēi-s-eh₂ ← PIE *(s)peh₁i-.
- The preterite of class VII strong verbs with ai, al or an plus a consonant, or ē¹.
- iz: OEng mēd, OHG miata "reward" (vs. OEng meord, Goth mizdō) ← PIE *misdʰós.
- Certain pronomial forms, e.g. OEng hēr "here".
- Words borrowed from Latin ē or e in the root syllable after a certain period (older loans also show ī).
Nasal vowels 
Whether and to what extent this distinction was phonemic is a matter of debate. Phonemic nasal vowels definitely occurred in Proto-Norse and Old Norse down to at least 1125 AD, the earliest possible time for the creation of the First Grammatical Treatise (which documents nasal vowels). Surface (possibly phonemic) nasal/non-nasal contrasts occurred in the West Germanic languages down through Proto-Anglo-Frisian of 400 AD or so.
There are apparent examples indicating that phonemic nasality must have occurred at some stage of Proto-Germanic, e.g. the three-way distinction of final -u/-ų/-un in *fehu "livestock" vs. *nahtų "night (acc.)" vs. *tehun "ten". Since final -ų comes from earlier -un while final -un comes from earlier -unt, it could be claimed that Proto-Germanic actually had an underlying phonemic contrast -u/-un/-unt and that the development of phonemic nasality occurred only after Proto-Norse split off. This makes it hard to account for the relative chronology of sound changes, however. The process of nasalisation must have occurred before the loss of word-final -t, because from earlier -nt, -n remained in the 3rd person plural ending, and also some numerals. And that change in turn must have followed the loss of word-final -a and -e, because earlier -at remained as -a in the nominative/accusative singular of adjectives (from which Gothic ƕa "what" by analogy). Therefore the analysis with word-final nasal vowels is most likely to be correct.
It is somewhat doubtful whether nasality was phonemic for overlong vowels. The later phonetic developments of word-final overlong vowels are the same whether they are reconstructed as nasal or not. Both -ô (adverbial suffix) and -ǫ̂ (genitive plural ending) develop the same way in all daughter languages, showing up as -ō in Gothic, as -a in Old English and Old Norse and as -o in Old High German. This probably indicates an early phonemic merger, possibly within Proto-Germanic times.
Proto-Germanic allowed the following clusters in initial and medial position:
- Plosive + l: pl, kl, fl, hl, sl, bl, gl, wl
- Plosive + r: pr, tr, kr, fr, þr, hr, br, dr, gr, wr
- Non-labial obstruent + w: tw, dw, kw, þw, hw, sw
- Velar + nasal, s + nasal: kn, hn, sm, sn
It allowed the following clusters in medial position only:
- Liquid + w: lw, rw
- Geminates: pp, tt, kk, ss, bb, dd, gg, mm, nn, ll, rr, jj, ww
- Consonant + j: pj, tj, kj, fj, þj, hj, zj, bj, dj, gj, mj, nj, lj, rj
It allowed the following clusters in medial and final position only:
- Fricative + obstruent: ft, ht, fs, hs, zd
- Nasal + obstruent: mp, mf, ms, mb, nt, nk, nþ, nh, ns, nd, ng (however nh was simplified to h, with nasalisation and lengthening of the previous vowel, in late Proto-Germanic)
- l + consonant: lp, lt, lk, lf, lþ, lh, ls, lb, ld, lg, lm
- r + consonant: rp, rt, rk, rf, rþ, rh, rs, rb, rd, rg, rm, rn
The s + voiceless plosive clusters, sp, st, sk, could appear in any position in a word.
Later developments 
Due to the emergence of a word-initial stress accent, vowels in unstressed syllables were gradually reduced over time, beginning at the very end of the Proto-Germanic period and continuing into the history of the various dialects. Already in Proto-Germanic, word-final /e/ and /ɑ/ had been lost, and /e/ had merged with /i/ in unstressed syllables. Vowels in third syllables were also generally lost before dialect diversification began, such as final -i of some present tense verb endings, and in -maz and -miz of the dative plural ending and 1st person plural present of verbs.
Word-final short nasal vowels were however preserved longer, as is reflected Proto-Norse which still preserved word-final -ą (horna on the Gallehus horns), while the dative plural appears as -mz (gestumz on the Stentoften Runestone). Somewhat greater reduction is found in Gothic, which lost all final-syllable short vowels except u. Old High German and Old English initially preserved unstressed i and u, but later lost them in long-stemmed words and then Old High German lost them in many short-stemmed ones as well, by analogy.
Old English shows indirect evidence that word-final -ą was preserved into the separate history of the language. This can be seen in the infinitive ending -an (< *aną) and the strong past participle ending -en (< *-anaz). Since the early Old English fronting of /ɑ/ to /æ/ did not occur in nasalized vowels or before back vowels, this created a vowel alternation because the nasality of the back vowel ą in the infinitive ending prevented the fronting of the preceding vowel: *-aną > *-an, but *-anaz > *-ænæ > *-en. Therefore, the Anglo-Frisian brightening must necessarily have occurred very early in the history of the Anglo-Frisian languages, before the loss of final -ą.
The outcome of final vowels and combinations in the various daughters is shown in the table below:
|a-stem masculine accusative singular||ą||-||a||-||a?||-||-|
|a-stem masculine nominative singular||az||s||az||r|
|i-stem masculine accusative singular||į||-||i?||-||i||i/-||e/-|
|i-stem nominative singular||iz||s||iz||r|
|u-stem accusative singular||ų||u||u?||-||u||u/-||u/-|
|u-stem nominative singular||uz||us||uz||r|
|1st person singular present of verbs||ō||a||o > u||-||o > u|
|ō-stem adjective accusative singular||ǭ||ō||a||ā||a||e|
|ō-stem accusative plural||ōz||ōs||ōz||ar|
|3rd person singular past of weak verbs||ē||a||e > i||i||a|
|a-stem dative singular||ai||ē||ē||e||e|
|short ja-stem neuter nominative singular||ją||i||ja||-||i > ī||i||e|
|short ja-stem masculine nominative singular||jaz||is > jis||jaz||r|
|i-stem nominative plural||īz||eis (=īs)||īz||ir||ī|
|long ja-stem masculine nominative singular||ijaz||ijaz|
|long ja-stem neuter nominative singular||iją||i||ija||i|
|3rd person singular past subjunctive||ī||ī|
|ō-stem nominative plural||ôz||ōs||ōz||ar|
|u-stem genitive singular||auz||aus|
Reconstructions are tentative and multiple versions with varying degrees of difference exist. All reconstructed forms are marked with an asterisk (*).
It is often asserted that the Germanic languages have a highly reduced system of inflections as compared with Greek, Latin, or Sanskrit. Although this is true to some extent, it is probably due more to the late time of attestation of Germanic than to any inherent "simplicity" of the Germanic languages. As an example, there are less than 500 years between the Gothic Gospels of 360 AD and the Old High Germanic Tatian of 830 AD, yet Old High Germanic, despite being the most archaic of the West Germanic languages, is missing a large number of archaic features present in Gothic, including dual and passive markings on verbs, reduplication in Class VII strong verb past tenses, the vocative case, and second-position (Wackernagel's Law) clitics. Many more archaic features may have been lost between the Proto-Germanic of 200 BC or so and the attested Gothic language. Furthermore, Proto-Romance and Middle Indic of the fourth century AD—contemporaneous with Gothic—were significantly simpler than Latin and Sanskrit, respectively, and overall probably no more archaic than Gothic. In addition, some parts of the inflectional systems of Greek, Latin, and Sanskrit were innovations that were not present in Proto-Indo-European.
General morphological features 
Proto-Germanic had six cases, three genders, three numbers, three moods (indicative, subjunctive (PIE optative), imperative), and two voices (active and passive (PIE middle)). This is quite similar to the state of Latin, Greek, and Middle Indic of c. 200 AD.
Nouns and adjectives were declined in (at least) six cases: vocative, nominative, accusative, dative, instrumental, genitive. The locative case had merged into the dative case, and the ablative may have merged with either the genitive, dative or instrumental cases. However, sparse remnants of the earlier locative and ablative cases are visible in a few pronominal and adverbial forms. Pronouns were declined similarly, although without a separate vocative form. The instrumental and vocative can be reconstructed only in the singular; the instrumental survives only in the West Germanic languages, and the vocative only in Gothic.
Verbs and pronouns had three numbers: singular, dual, and plural. Although the pronominal dual survived into all the oldest languages, the verbal dual survived only into Gothic, and the (presumed) nominal and adjectival dual forms were lost before the oldest records. As in the Italic languages, it may have been lost before Proto-Germanic became a different branch at all.
Consonant and vowel alternations 
Several sound changes occurred in the history of Proto-Germanic that were triggered only in some environments but not in others. Some of these were grammaticalised while others were still triggered by phonetic rules and were partially allophonic or surface filters.
Probably the most far-reaching alternation was between voiceless and voiced fricatives, known as Grammatischer Wechsel and triggered by the earlier operation of Verner's law. It was found in various environments:
- In the person-and-number endings of verbs, which were voiceless in weak verbs and voiced in strong verbs.
- Between different grades of strong verbs. The voiceless alternants appeared in the present and past singular indicative, the voiced alternants in the remaining past tense forms.
- Between strong verbs (voiceless) and causative verbs derived from them (voiced).
- Between verbs and derived nouns.
- Between the singular and plural forms of some nouns.
Another form of alternation was triggered by the Germanic spirant law, which continued to operate into the separate history of the individual daughter languages. It is found in environments with suffixal -t, including:
- The second-person singular past ending *-t of strong verbs.
- The past tense of weak verbs with no vowel infix in the past tense.
- Nouns derived from verbs by means of the suffixes *-tiz, *-tuz, *-taz, which also possessed variants in -þ- and -d- when not following an obstruent.
An alternation not triggered by sound change was Sievers' law, which caused alternation of suffixal -j- and -ij- depending on the length of the preceding part of the morpheme. If preceded within the same morpheme by only short vowel followed by a single consonant, -j- appeared. In all other cases, such as when preceded by a long vowel or diphthong, by two or more consonants, or by more than one syllable, -ij- appeared. The distinction between morphemes and words is important here, as the alternant -j- appeared also in words that contained a distinct suffix that in turn contained -j- in its second syllable. A notable example was the verb suffix *-atjaną, which retained -j- despite being preceded by two syllables in a fully formed word.
Related to the above was the alternation between -j- and -i-, and likewise between -ij- and -ī-. This was caused by the earlier loss of -j- before -i-, and appeared whenever an ending was attached to a verb or noun with an -(i)j- suffix (which were numerous). Similar, but much more rare, was an alternation between -aV- and -aiC- from the loss of -j- between two vowels, which appeared in the present subjunctive of verbs: *-aų < *-ajų in the first person, *-ai- in the others. A combination of these two effects created an alternation between -ā- and -ai- found in class 3 weak verbs, with -ā- < -aja- < -əja- and -ai- < -əi- < -əji-.
I-mutation was the most important source of vowel alternation, and continued well into the history of the individual daughter languages (although it was either absent or not apparent in Gothic). In Proto-Germanic, only -e- was affected, which was raised by -i- or -j- in the following syllable. Examples are numerous:
- Verb endings beginning with -i-: present second and third person singular, third person plural.
- Noun endings beginning with -i- in u-stem nouns: dative singular, nominative and genitive plural.
- Causatives derived from strong verbs with a -j- suffix.
- Verbs derived from nouns with a -j- suffix.
- Nouns derived from verbs with a -j- suffix.
- Nouns and adjectives derived with a variety of suffixes including -il-, -iþō, -į̄, -iskaz, -ingaz.
The system of nominal declensions was largely inherited from PIE. Primary nominal declensions were the stems in /a/, /ō/, /n/, /i/, and /u/. The first three were particularly important and served as the basis of adjectival declension; there was a tendency for nouns of all other classes to be drawn into them. The first two had variants in /ja/ and /wa/, and /jō/ and /wō/, respectively; originally, these were declined exactly like other nouns of the respective class, but later sound changes tended to distinguish these variants as their own subclasses. The /n/ nouns had various subclasses, including /ōn/ (masculine and feminine), /an/ (neuter), and /īn/ (feminine, mostly abstract nouns). There was also a smaller class of root nouns (ending in various consonants), nouns of relationship (ending in /er/), and neuter nouns in /z/ (this class was greatly expanded in German). Present participles, and a few nouns, ended in /nd/. The neuter nouns of all classes differed from the masculines and feminines in their nominative and accusative endings, which were alike.
|Case||Nouns in -a-||Nouns in -i-|
Adjectives agree with the noun they qualify in case, number, and gender. Adjectives evolved into strong and weak declensions, originally with indefinite and definite meaning, respectively. As a result of its definite meaning, the weak form came to be used in the daughter languages in conjunction with demonstratives and definite articles. The terms "strong" and "weak" are based on the later development of these declensions in languages such as German and Old English, where the strong declensions have more distinct endings. In the proto-language, as in Gothic, such terms have no relevance. The strong declension was based on a combination of the nominal /a/ and /ō/ stems with the PIE pronominal endings; the weak declension was based on the nominal /n/ declension.
|Strong Declension||Weak Declension|
Proto-Germanic had a demonstrative which could serve as both a demonstrative adjective and a demonstrative pronoun. In daughter languages, it evolved into the definite article, and underlies the English determiners the and that. In the North and West Germanic languages (but not in Gothic), a second demonstrative with proximal semantics (i.e. "this" as opposed to "that") evolved by appending -si to the Proto-Germanic demonstrative, with complex subsequent developments in the various daughter languages. This new demonstrative underlies the English determines this, these and those. (Originally, those was masculine plural this and these was feminine plural this.)
|Dative||*þesmō, *þasmō||*þemiz, *þaimiz||*þezai||*þaimiz|
Proto-Germanic had only two tenses (past and present), compared to the six or seven in Greek, Latin, and Sanskrit. Some of this difference is due to deflexion, featured by a loss of tenses present in Proto-Indo-European. For example, Donald Ringe assumes for Proto-Germanic an early loss of the PIE imperfect aspect (something that also occurred in most other branches), followed by merging of the aspectual categories present-aorist and the mood categories indicative-subjunctive. (This assumption allows him to account for cases where Proto-Germanic has present indicative verb forms that look like PIE aorist subjunctives.)
However, many of the tenses of the other languages (e.g. future, future perfect, pluperfect, Latin imperfect) are not cognate with each other and represent separate innovations in each language. For example, the Greek future uses an /s/ ending, apparently derived from a desiderative construction that in PIE was part of the system of derivational morphology (not the inflectional system); the Sanskrit future uses an /sy/ ending, from a different desiderative verb construction and often with a different ablaut grade from Greek; while the Latin future uses endings derived either from the PIE subjunctive or from the PIE verb /bʱuː/ "to be". Similarly, the Latin imperfect and pluperfect stem from Italic innovations and are not cognate with the corresponding Greek or Sanskrit forms; and while the Greek and Sanskrit pluperfect tenses appear cognate, there are no parallels in any other Indo-European languages, leading to the conclusion that this tense is either a shared Greek-Sanskrit innovation or separate, coincidental developments in the two languages. In this respect, Proto-Germanic can be said to be characterized by the failure to innovate new synthetic tenses as much as the loss of existing tenses. Later Germanic languages did innovate new tenses, derived through periphrastic constructions, with Modern English likely possessing the most elaborated tense system ("Yes, the house will still be being built a month from now").
Verbs in Proto-Germanic were divided into two main groups, called "strong" and "weak", according to the way the past tense is formed. Strong verbs use ablaut (i.e. a different vowel in the stem) and/or reduplication (derived primarily from the Proto-Indo-European perfect), while weak verbs use a dental suffix (now generally held to be a reflex of the reduplicated imperfect of PIE *dheH1- originally "put", in Germanic "do"). Strong verbs were divided into seven main classes while weak verbs were divided into five main classes (although no attested language has more than four classes of weak verbs). Strong verbs generally have no suffix in the present tense, although some have a -j- suffix that is a direct continuation of the PIE -y- suffix, and a few have an -n- suffix or infix that continues the -n- infix of PIE. Almost all weak verbs have a present-tense suffix, which varies from class to class. An additional small, but very important, group of verbs formed their present tense from the PIE perfect (and their past tense like weak verbs); for this reason, they are known as preterite-present verbs. All three of the previously mentioned groups of verbs—strong, weak and preterite-present—are derived from PIE thematic verbs; an additional very small group derives from PIE athematic verbs, and one verb *wiljaną "to want" forms its present indicative from the PIE optative mood.
Proto-Germanic verbs have three moods: indicative, subjunctive and imperative. The subjunctive mood derives from the PIE optative mood. Indicative and subjunctive moods are fully conjugated throughout the present and past, while the imperative mood existed only in the present tense and lacked first-person forms. Proto-Germanic verbs have two voices, active and passive, the latter deriving from the PIE mediopassive voice. The Proto-Germanic passive existed only in the present tense (an inherited feature, as the PIE perfect had no mediopassive). On the evidence of Gothic—the only Germanic language with a reflex of the Proto-Germanic passive—the passive voice had a significantly reduced inflectional system, with a single form used for all persons of the dual and plural. Note that, although Old Norse has an inflected mediopassive, it is not inherited from Proto-Germanic, but is an innovation formed by attaching the reflexive pronoun to the active voice.
Although most Proto-Germanic strong verbs are formed directly from a verbal root, weak verbs are generally derived from an existing noun, verb or adjective (so-called denominal, deverbal and deadjectival verbs). For example, a significant subclass of Class I weak verbs are (deverbal) causative verbs. These are formed in a way that reflects a direct inheritance from the PIE causative class of verbs. PIE causatives were formed by adding an accented suffix -éi̯e/éi̯o to the o-grade of a non-derived verb. In Proto-Germanic, causatives are formed by adding a suffix -j/ij- (the reflex of PIE -éi̯e/éi̯o) to the past-tense ablaut (mostly with the reflex of PIE o-grade) of a strong verb (the reflex of PIE non-derived verbs), with Verner's Law voicing applied (the reflex of the PIE accent on the -éi̯e/éi̯o suffix). Examples:
- *bītaną (I) "to bite" → *baitijaną "to bridle, yoke, restrain", i.e. "to make bite down"
- *rīsaną (I) "to rise" → *raizijaną "to raise", i.e. "to cause to rise"
- *beuganą (II) "to bend" → *baugijaną "to bend (transitive)"
- *brinnaną (III) "to burn" → *brannijaną "to burn (transitive)"
- *frawerþaną (III) "to perish" → *frawardijaną "to destroy", i.e. "to cause to perish"
- *nesaną (V) "to survive" → *nazjaną "to save", i.e. "to cause to survive"
- *ligjaną (V) "to lie down" → *lagjaną "to lay", i.e. "to cause to lie down"
- *faraną (VI) "to travel, go" → *fōrijaną "to lead, bring", i.e. "to cause to go"
- *faraną (VI) "to travel, go" → *farjaną "to carry across", i.e. "to cause to travel" (an archaic instance of the o-grade ablaut used despite the differing past-tense ablaut)
- *grētaną (VII) "to weep" → *grōtijaną "to cause to weep"
- *lais (I, preterite-present) "(s)he knows" → *laizijaną "to teach", i.e. "to cause to know"
As in other Indo-European languages, a verb in Proto-Germanic could have a preverb attached to it, modifying its meaning (cf. e.g. *fra-werþaną "to perish", derived from *werþaną "to become"). In Proto-Germanic, the preverb was still a clitic that could be separated from the verb (as also in Gothic, as shown by the behavior of second-position clitics, e.g. diz-uh-þan-sat "and then he seized", with clitics uh "and" and þan "then" interpolated into dis-sat "he seized") rather than a bound morpheme that is permanently attached to the verb (as in all other Germanic languages). At least in Gothic, preverbs could also be stacked one on top of the other (similar to Sanskrit, different from Latin), e.g. ga-ga-waírþjan "to reconcile".
An example verb: *nemaną "to take" (class IV strong verb).
|Present||1st sing||*nemō||*nemôi? *nemai?||*nema-ų||???||–|
|1st dual||*nemōz (?)||*nemandai||*nemaiw||*nemaindau?||–|
|2nd dual||*nemadiz (?)||*nemandai||*nemaidiz (?)||*nemaindau?||*nemadiz?|
|Past||1st sing||*nam||–||*nēmijų (?; or *nēmį̄??)||–||–|
|1st dual||*nēmū (?)||*nēmīw|
|2nd dual||*nēmudiz (?)||*nēmīdiz (?)|
|First person||Second person||Third person|
1 – Unstressed variant
Schleicher's PIE fable rendered into Proto-Germanic 
August Schleicher wrote a fable in the PIE language he had just reconstructed, which though it has been updated a few times by others still bears his name. Below is a rendering of this fable into Proto-Germanic.
The first is a direct phonetic evolution of the Indo-European text. It does not take into account various idiomatic and grammatical shifts that occurred over the period. For example, the original text uses the imperfect tense, which disappeared in Proto-Germanic. The second version takes these differences into account, and is therefore closer to the language the Germanic people would have actually spoken.
Proto-Germanic, phonetic evolution only
- Awiz ehwōz-uh: awiz, hwisi wullō ne est, spihi ehwanz, ainą kurų wagą wegandų, ainą-uh mekǭ burą, ainą-uh gumanų ahu berandų. Awiz nu ehwamaz wiuhi: hert agnutai mek, witandī ehwanz akandų gumanų. Ehwōz weuhą: hludi, awi! hert agnutai uns witundumaz: gumô, fadiz, wullǭ awją hwurniudi sibi warmą westrą. Awją-uh wullō ne isti. þat hehluwaz awiz akrą buki.
Proto-Germanic, with grammar and vocabulary modernised
- Awiz ehwōz-uh: awiz, sō wullǭ ne habdē, sahw ehwanz, ainanǭ kurjanǭ wagną teuhandų, ainanǭ-uh mikilǭ kuriþǭ, ainanǭ-uh gumanų sneumundô berandų. Awiz nu ehwamaz sagdē: hertô sairīþi mek, sehwandē ehwanz akandų gumanų. Ehwōz sagdēdun: gahauzī, awi! hertô sairīþi uns sehwandumiz: gumô, fadiz, uz awīz wullō wurkīþi siz warmą wastijǭ. Awiz-uh wullǭ ne habaiþi. þat hauzidaz awiz akrą flauh.
- The Sheep and the Horses: a sheep that had no wool saw horses, one pulling a heavy wagon, one carrying a big load, and one carrying a man quickly. The sheep said to the horses: “My heart pains me, seeing a man driving horses”. The horses said: “Listen, sheep, our hearts pain us when we see this: a man, the master, makes the wool of the sheep into a warm garment for himself. And the sheep has no wool”. Having heard this, the sheep fled into the plain.
See also 
- Another, less common name used in English-language literature by a few noteworthy scholars is (Primitive) Germanic Parent Language. For example, see Bloomfield, Leonard (1984). Language. Chicago and London: The University of Chicago Press. pp. 298–299. Unknown parameter
- Comrie, Bernard (editor) (1987). The World's Major Languages. New York, New York: Oxford University Press. pp. 69–70. ISBN 0-19-506511-5.
-  Perfect Phylogenetic Networks: A New Methodology for Reconstructing the Evolutionary History of Natural Languages – Luay Nakhleh,Don Ringe & Tandy Warnow, 2005, Language- Journal of the Linguistic Society of America, Volume 81, Number 2, June 2005
- Ringe 2006, p. 67.
- Described in this and the linked articles but see Kleinman.
- Lehmann, W. P. (January – March, 1961). "A Definition of Proto-Germanic: A Study in the Chronological Delimitation of Languages". Language 37 (1): 67–74. doi:10.2307/411250.
- Bennett, William H. (May 1970). "The Stress Patterns of Gothic". PMLA 85 (3): 463–472. doi:10.2307/1261448. JSTOR 1261448. First page and abstract no charge.
- Antonsen, Elmer H. (January – March, 1965). "On Defining Stages in Prehistoric German". Language 41 (1): 19–36. doi:10.2307/411849.
- Antonsen, Elmer H. (2002). Runes and Germanic Linguistics. Walter de Gruyter. pp. 26–30. ISBN 3-11-017462-6. This presentation also summarizes Lehmann's view.
- Antonsen (2000) page 28 table 9.
- "Languages of the World: Germanic languages". The New Encyclopædia Britannica. Chicago, IL, United States: Encyclopædia Britannica, Inc. 1993. ISBN 0-85229-571-5. This long-standing, well-known article on the languages can be found in almost any edition of Britannica.
- Bell-Fialkoll (Editor), Andrew (2000). The Role of Migration in the History of the Eurasian Steppe: Sedentary Civilization v. "Barbarian" and Nomad. Palgrave Macmillan. p. 117. ISBN 0-312-21207-0. Note that the term "pre-Germanic" is equivocal, meaning, as here, either prior to the Indo-European ancestors or Indo-European but prior to Proto-Germanic.
- Kinder, Hermann; Werner Hilgemann; Ernest A. Menze (Translator); Harald and Ruth Bukor (Maps) (1988). The Penguin atlas of world history. Harmondsworth: Penguin Books. Volume 1 page 109. ISBN 0-14-051054-0.
- Kinder book
- Ringe 2006, p. 296; Lane, George S (1933). "The Germano-Celtic Vocabulary". Language 9: 244–264.
- Watkins, Calvert (2000). "Appendix I: Indo-European Roots: reg-". The American Heritage Dictionary of the English Language: Fourth Edition.
- The etymologies are to be found mainly in Green, Dennis Howard (2000). Language and History in the Early Germanic World. Cambridge: Cambridge University Press. pp. 149–164. One is in Ringe 2006, p. 296.
- Orel 2003, *paido-. This word gave: Old English pād, Old Saxon pēda, Old High German pfeit, Bavarian Pfoad, Gothic paida 'coat'.
- The preceding etymologies come from Orel 2003, which is arranged in alphabetic order by root.
- Cunliffe, Barry (2008). Europe Between the Oceans 9000 BC - AD 1000. New Haven: Yale University Press. pp. 303–7, 352.
- Ringe 2006, p. 149
- Ringe 2006, p. 278
- Vladimir Orel, A Handbook of Germanic Etymology (Leiden, Netherlands: Brill, 2003), 251.
- Feist was proposing the idea as early as 1913 but his classical paper on the subject is Feist, Sigmund (1932). "The Origin of the Germanic Languages and the Europeanization of North Europe". Language 8: 245–254. doi:10.2307/408831. A brief biography and presentation of his ideas can be found in Mees, Bernard (2003), "Stratum and Shadow: The Indo-European West: Sigmund Feist", in Andersen, Henning, Language Contacts in Prehistory: Studies in Stratigraphy, John Benjamin Publishing Company, pp. 19–21, ISBN 1-58811-379-5
- On eu and iu see Cercignani 1973.
- While the classification varies somewhat the consonants do not; for example, coronals are sometimes listed as dentals and alveolars while velars and labiovelars are sometimes combined under dorsals.
- Van Kerckvoorde, Colette M. (1993). An Introduction to Middle Dutch. Berlin and New York: Mouton de Gruyter. p. 123. ISBN 3-11-013535-3.
- McMahon, April M.S. (1994). Understanding Language Change. Cambridge University Press. p. 227. ISBN 0-521-44665-1.
- Trask, Robert Lawrence (2000). The Dictionary of Historical and Comparative Linguistics. Chicago, London: Fitzroy Dearborn. p. 122. ISBN 1-57958-218-4.
- Kraehenmann, Astrid (2003). Quantity and Prosodic Asymmetries is Alemannic: Synchronic and Diachronic. Berlin and New York: Mouton de Gruyter. p. 58. ISBN 3-11-017680-7.
- Ringe 2006, p. 100
- Ringe 2006
- Ringe 2006, p. 92, 215
- On i and e see Cercignani 1979.
- Ringe 2006, p. 295
- Fortson, Benjamin W. IV (2010). Indo-European Language and Culture: An Introduction. Blackwell Textbooks in Linguistics (2nd ed.). Global: Blackwell Publishing. p. 342.
- Hall, T.A. (2000), "The Distribution of Trimoraic Syllables in German and English as Evidence for the Phonological Word", in Hall, T. A.; Rochoń, Marzena, Investigations in Prosodic Phonology: The Role of the Foot and the Phonological Word, ZAS Papers in Linguistics 19, Berlin: ZAS, Zentrum für Allgemeine Sprachwissenschaft (ZAS), pp. 41–90
- Liberman, Anatoly (1982). Germanic Accentology. Minneapolis. p. 140. Text " University of Minnesota Press " ignored (help)
- Purczinsky, Julius (1993). "Proto-Indo-European Circumflex Intonation or Bisyllabicity". Word 44 (1): 53.
- But see Cercignani 1972
- Lehmann, Winfred P. (2007). "The Origin of PGmc. Long Close e". Proto-Indo-European phonology. Austin: Linguistics Research Center.
- Ringe, Donald (2006). From Proto-Indo-European to Proto-Germanic. Oxford University Press. ISBN 0-19-928413-X.
- Bennett, William Holmes (1980). An Introduction to the Gothic Language. New York: Modern Language Association of America.
- Campbell, A. (1959). Old English Grammar. London: Oxford University Press.
- Cercignani, Fausto (1972). "Indo-European ē in Germanic". Zeitschrift für vergleichende Sprachforschung 86 (1): 104–110.
- Cercignani, Fausto (1973). "Indo-European eu in Germanic". Indogermanische Forschungen 78: 106–112.
- Cercignani, Fausto (1979). "Proto-Germanic */i/ and */e/ Revisited". Journal of English and Germanic Philology 78 (1): 72–82.
- Krahe, Hans and Meid, Wolfgang. Germanische Sprachwissenschaft, 2 vols., de Gruyter, Berlin (1969).
- Orel, Vladimir (2003). A Handbook of Germanic Etymology. Leiden; Boston; Internet: Brill; Internet Archive.
- Plotkin, Vulf (2008). The Evolution of Germanic Phonological Systems: Proto-Germanic, Gothic, West Germanic, and Scandinavian. Lewiston: Edwin Mellen.
- Ramat, Anna Giacalone and Paolo Ramat (Eds.) (1998). The Indo-European Languages. Routledge. ISBN 0-415-06449-X.
- Ringe, Donald A. (2006). From Proto-Indo-European to Proto-Germanic. Linguistic history of English, v. 1. Oxford: Oxford University Press. ISBN 0-19-955229-0.
- Voyles, Joseph B. (1992). Early Germanic Grammar. San Diego: Academic Press. ISBN 0-12-728270-X.
- Guus, Kroonen (Expected November 2012). Etymological Dictionary of Proto-Germanic. Leiden Indo-European Etymological Dictionary Series, 11. Brill Academic Publishers. ISBN 978-90-04-18340-7.
- W.P. Lehmann & J. Slocum (eds.) A Grammar of Proto-Germanic (Online version)
- Proto-Germanic nominal and pronominal paradigms
- A dictionary of Proto-Germanic (in German)
- Another dictionary of Proto-Germanic
- Charles Prescott. "Germanic and the Ruki Dialects"
- Table: Germanic & PIE -ia and -ja stems compared across reference sources