|Era||Evolved into Early Middle Japanese during the Heian period|
Old Japanese (上代日本語 Jōdai Nihon-go) is the oldest attested stage of the Japanese language. It is attested in documents from the Nara period (8th century). It evolved into Early Middle Japanese in the succeeding Heian period, although the precise separation of these two languages is controversial. Old Japanese was an early member of the Japonic family; no conclusive links to other language families have been demonstrated.
Old Japanese was written using Chinese characters, using an increasingly standardized and phonetic form that eventually evolved into man'yōgana. Typically for a Japonic language and for a step in the evolutionary line of modern Japanese, Old Japanese was a primarily agglutinative language with subject–object–verb word ordering. However, the language was marked by a few phonemic differences from later forms of Japanese, such as a simpler syllable structure and distinctions between several pairs of syllables pronounced identically in Early Middle Japanese and later. The phonetic realization of this differentiation is uncertain.
- 1 Sources and dating
- 2 Writing system
- 3 Phonology
- 4 Grammar
- 5 Dialects
- 6 See also
- 7 Notes
- 8 References
- 9 Further reading
- 10 External links
Sources and dating
Linguistic changes are gradual, and the periodization of Japanese is "both delicate and controversial", with multiple competing methods and criteria for division. For both practical and conventional reasons, these divisions often correlate to political events, particularly shifts in power or changes of capital.
Old Japanese is usually defined as the language of the Nara period (710–794), when the capital was Heijō-kyō (present-day Nara). This is the period of the earliest connected texts in Japanese, the 112 songs included in the Kojiki (712). The other major literary sources of the period are the 128 songs included in the Nihon Shoki (720) and the Man'yōshū (c. 759), a compilation of over 4,500 poems. Shorter samples are 25 poems in the Fudoki (720) and the 21 poems of the Bussokuseki-kahi (c. 752). The latter has the virtue of being an original inscription, whereas for all the other texts the oldest surviving manuscripts are the results of centuries of copying, with the attendant risk of scribal errors. Prose texts are more limited, but are thought to reflect the syntax of Old Japanese more accurately than verse. The most important are the 27 Norito (liturgies) recorded in the Engishiki (compiled in 927) and the 62 Senmyō (imperial edicts) recorded in the Shoku Nihongi (797).
A limited number of Japanese words, mostly personal names and place names, are recorded phonetically in ancient Chinese texts such as the "Wei Zhi" portion of the Records of the Three Kingdoms (3rd century AD), but the transcriptions by Chinese scholars are unreliable. The oldest surviving native inscriptions, dating from the 5th or early 6th centuries, include those on the Suda Hachiman Shrine Mirror, the Inariyama Sword and the Eta Funayama Sword. These inscriptions are written in Classical Chinese, but contain several Japanese names transcribed phonetically using Chinese characters. Such inscriptions become more common from the Suiko period (592–628). These fragments are usually considered a form of Old Japanese.
Artifacts inscribed with Chinese characters dated as early as the 1st century AD have been found in Japan, but it appears that detailed knowledge of the script did not arrive in the islands until the early 5th century. According to the Kojiki and Nihon Shoki, it was brought by scholars from Baekje (southwest Korea). The earliest texts found in Japan are written in Classical Chinese, probably by immigrant scribes. Later "hybrid" texts show the influence of Japanese grammar, such as the word order (for example, placing the verb after the object).
Chinese and Koreans had long used Chinese characters to write non-Chinese terms and proper names phonetically, by selecting characters for Chinese words that sounded like each syllable. Koreans also used the characters phonetically to write Korean particles and inflections added to Chinese texts as an aid to reading (Idu script). In Japan, the practice was developed into man'yōgana, a complete script for the Japanese language using Chinese characters phonetically, and the ancestor of modern kana syllabaries. This system was already in use in the verse parts of the Kojiki (712) and the Nihon Shoki (720). For example, the first line of the first poem in the Kojiki was written with five characters:
|'many clouds rising'|
This method of writing Japanese syllables by using characters for their Chinese sounds (ongana) was supplemented with indirect methods in the complex mixed script of the Man'yōshū (c. 759).
In man'yōgana, each Old Japanese syllable was represented by a Chinese character. Although any one of several characters could be used for a given syllable, a careful analysis revealed that 88 syllables were distinguished in the Kojiki:
The system has the same gaps of yi and wu found in later forms of Japanese. However, many syllables that have a modern i, e or o occurred in two forms, termed types A (甲 kō) and B (乙 otsu), denoted by subscripts 1 and 2 respectively in the above table. The syllables mo1 and mo2 are not distinguished in the slightly later Nihon Shoki and Man'yōshū, reducing the syllable count to 87. All of these pairs had merged by the Early Middle Japanese of the Heian period.
|Kindaichi, Miller, Ōno||i||ï||e||ë||o||ö|
|Frellesvig and Whitman||i||wi||ye||e||wo||o|
There is no consensus on the pronunciation of the syllables distinguished by man'yōgana. One difficulty is that the Middle Chinese pronunciations of the characters used are also disputed, and since their reconstruction is partly based on Sino-Japanese pronunciations, there is a danger of circular reasoning. Additional evidence has been drawn from phonological typology, subsequent developments in the Japanese pronunciation, and comparative study of the Ryukyuan languages.
Old Japanese had open syllables, of the form (C)V, subject to additional restrictions:
- Words do not begin with r or the voiced plosives b, d, z and g, with the exception of a few loanwords.
- A bare vowel does not occur except for word-initially: vowel sequences were not permitted.
In 1934, Arisaka Hideyo proposed a set of phonological restrictions permitted in a single morpheme. Arisaka's Law states that -o2 is generally not found in the same morpheme as -a, -o1 or -u. Some scholars have interpreted this as a vestige of earlier vowel harmony, but it is very different from patterns observed in e.g. the Turkic languages.
The Chinese characters chosen to write syllables with the Old Japanese vowel a suggest that it was an open unrounded vowel /a/. The vowel u was a close rounded back vowel /u/, unlike the unrounded /ɯ/ of Modern Standard Japanese.
Several hypotheses have been advanced to explain the A/B distinctions made in man'yōgana. The issue is hotly debated, and there is no consensus. The widely accepted traditional view, first advanced by Kyōsuke Kindaichi in 1938, is that there were eight pure vowels, with the type B vowels being more central than their type A counterparts. Others, beginning in the 1930s but more commonly since the work of Roland Lange in 1968, attribute the type A/B distinction to medial or final glides /j/ and /w/. The diphthong proposals are often connected to hypotheses about pre-Old Japanese, but all exhibit an uneven distribution of glides.
|i||ï||e||ë||o||ö||Kindaichi (1938), Miller (1967)|
|ji||i||je||e||wo||o||Lange (1968, 1973)|
|i||wi||je||e||wo||o||Unger (1977), Frellesvig and Whitman (2008)|
The distinction between mo1 and mo2 is only seen in Kojiki and vanished afterwards. Distributionally, there may have once been *po1, *po2, *bo1 and *bo2. If this is true, then a distinction was made between Co1 and Co2 for all consonants C except for w. Some take this as support that Co1 may have represented Cwo.
Most scholars derive the Old Japanese vowel system from an earlier four-vowel system, with the most common Old Japanese vowels a, u, i1 and o2 reflecting earlier *a, *u, *i and *ə respectively. Internal reconstruction suggests that the other, less common, Old Japanese vowels are derived from fusions of these vowels. For example, the place name take2ti is derived from a compound of taka- 'high' and iti 'market'. Another piece of evidence is that many nouns have different forms when used independently and when used within compounds. An example is sake2 'rice wine', which becomes saka- in compounds such as sakaduki 'saké cup'. In such cases the bound form is considered basic, and the independent form may be explained by postulating a suffix *-i that fused with the final vowel of the root. The following reductions are proposed:
- i2 < *ui: kami2/kamu- 'god, spirit', mi2/mu- 'eye', nagi2/nagu- 'a calm'.
- i2 < *əi: ki2/ko2- 'tree', yomi2/yomo2- 'Hades'.
- e1 < *ia: sake1ri 'blooming' < saki1 'to bloom' + ari 'to be'.
- e1 < *iə: pe1ku (proper name) < pi1 'sun' + o2ki1 'put'.
- e2 < *ai: me2/ma- 'eye', ame2/ama- 'heaven', ame2/ama- 'rain', kage2/kaga- 'shade'.
- o1 < *ua: kazo1pu 'to count' < kazu 'number' + apu 'to combine'.
- o1 < *uə: sito1ri 'kind of native weaving' < situ 'native weaving' + ori 'weaving'.
There are also alternations suggesting e2 < *əi, such as:
- se2/so2- 'back', me2/mo2- 'bud'
Some authors believe these belong to an earlier layer than i2 < *əi, while others reconstruct two central vowels *ə and *ɨ, which merge everywhere except before *i. Other authors attribute this variation to different reflexes in different dialects, noting that *əi yields e in Ryukyuan languages. Some authors also suggest that *e and *o are required to account for word-final e1 and o1 respectively.
Miyake 2003 reconstructs the following inventory, in addition to a zero vowel-initial onset /∅/:
The voiceless obstruents /p, t, s, k/ had the voiced prenasalized counterparts /ᵐb, ⁿd, ⁿz, ᵑɡ/. This prenasalization was still present in the late 17th century (according to the Korean textbook Chephay sine), and is found in some modern Japanese and Ryukyuan dialects, but has disappeared in Modern Japanese, except for the intervocalic nasal stop allophone [ŋ] of /ɡ/. The sibilants /s/ and /ⁿz/ may have been palatalized before e and i.
Comparative evidence from Ryukyuan languages suggests that Old Japanese p derives from an earlier voiceless bilabial stop *p. There is general agreement that word-initial p had become a voiceless bilabial fricative [ɸ] by Early Middle Japanese, as suggested by its transcription as f in later Portuguese works and as ph or hw in the Korean textbook Chephay sine. In Modern Standard Japanese, it is romanized as h and has different allophones before various vowels. In medial position, it became [w] in Early Middle Japanese, and has since disappeared except before a. Many scholars argue that p had already lenited to [ɸ] by the Old Japanese period, but Miyake argues that it was still a stop.
Internal reconstruction suggests that the Old Japanese voiced obstruents, which always occurred in medial position, arose from weakening of earlier nasal syllables before voiceless obstruents:
- b /ᵐb/ < *-mVp-, *-nVp-: e.g. abi1ki1 'trawling' < ami1 'net' + pi1ki1 'pull'.
- d /ⁿd/ < *-mVt-, *-nVt-: e.g. yamadi 'mountain path' < yama 'mountain' + mi1ti 'path'.
- z /ⁿz/ < *-mVs-, *-nVs-: e.g. the title murazi < mura 'village' + nusi 'master'.
- g /ᵑɡ/ < *-mVk-, *-nVk-.
In some cases there is no evidence for a preceding vowel, leading some scholars to posit final nasals at the earlier stage.
Some linguists suggest that Old Japanese w and y derive respectively from *b and *d at some point before the oldest inscriptions in the 6th century. Southern Ryukyuan varieties such as Miyako, Yaeyama and Yonaguni retain /b/ and /d/ in these words:
- ba 'I' and bata 'stomach' corresponding to Old Japanese wa and wata
- Yonaguni da 'house', du 'hot water' and dama 'mountain' corresponding to Old Japanese ya, yu and yama
However, many linguists, especially in Japan, argue that the Southern Ryukyuan voiced stops are local innovations. Some supporters of *b and *d also add *z and *g, both disappearing in Old Japanese, for reasons of symmetry. However, there is very little Japonic evidence for these.
- wa + ga + ipe1 → wagape1
- ake + u → aku
- to2ko2 + ipa → to2kipa
- ko2 + i → ki
Although modern Japanese dialects have pitch accent systems, these are usually not shown in man'yōgana. However, in one part of the Nihon Shoki, the Chinese characters appear to be chosen to represent a pitch pattern similar to that recorded in the Ruiju Myōgishō, a dictionary compiled in the late 11th century. In this section, a low pitch syllable is represented by a character with the Middle Chinese level tone, and a high pitch is represented by a character with one of the other three Middle Chinese tones. (A similar division was used in the tone patterns of Chinese poetry, which were emulated by Japanese poets in the late Asuka period.) Thus it appears that the Old Japanese accent system was similar to that of Early Middle Japanese.
This section needs expansion. You can help by adding to it. (November 2014)
As in later forms of Japanese, Old Japanese word order was predominantly subject–object–verb, with adjectives and adverbs preceding the nouns and verbs they modify, and auxiliary verbs and particles consistently appended to the main verb.
Many Old Japanese pronouns had both a short form and a longer form with attached -re of uncertain etymology. Where the pronoun occurred in isolation, the longer form would be used. With genitive particles or in nominal compounds, the short form was used, whereas in other situations either form was possible.
- The first person pronouns were a(re) and wa(re), were used for the singular and plural respectively, though with some overlap. The wa- forms were also used reflexively, suggesting that wa was originally an indefinite pronoun and gradually replaced a.
- The second person pronoun was na(re).
- The third person pronoun si was much less commonly used than the non-proximal demonstrative so2, from which it was derived.
- There were also an interrogative pronoun ta(re) and a reflexive pronoun o2no2.
In Early Middle Japanese, the non-proximal so- forms were re-interpreted as hearer-based (medial), and the formerly speaker-based forms divided into proximal ko- forms and distal ka-/a- forms, yielding the three-way distinction still found in Modern Japanese.
Old Japanese had a richer system of verbal suffixes than later forms of Japanese. Old Japanese verbs used inflection for modal and conjunctional purposes. Other categories, such as voice, tense, aspect and mood, were expressed using optional suffixed auxiliaries, which were also inflected.
As in later forms of Japanese, Old Japanese verbs had a large number of inflected forms. In traditional Japanese grammar, these are represented by six forms (katsuyōkei, 活用形) from which all the others may be derived, in a similar fashion to the principal parts used for Latin and other languages:
- Mizenkei (irrealis)
- This form never occurs in isolation, but only as a stem to which several particles and auxiliaries are attached. Unger calls it a "pseudostem", because the purported inflection was originally an initial *a of the suffixes attached to this stem.
- Renyoukei (adverbial, infinitive)
- This form was used as the infinitive. It also served as a stem for auxiliaries expressing tense and aspect.
- Shushikei (conclusive, predicative)
- This form was used as the main verb concluding a declarative sentence. It was also used before modal extensions, final particles and some conjunctional particles. The conclusive form merged with the attributive form by about 1600, but the distinction is preserved in Ryukyuan languages and the Hachijōjima dialects.
- Rentaikei (attributive, adnominal)
- This form was used as the verb in a nominalized clause or a clause modifying a noun. It was also used before most conjunctional particles.
- Izenkei (realis, exclamatory, subjunctive)
- This form was used as the main verb in an exclamatory sentence or as the verb in an adverbial clause. It also served as a stem for the particles -ba (provisional) and -do (concessive).
- Meireikei (imperative)
- This form expressed the imperative mood.
This system has been criticized because the six forms are not equivalent, with one being solely a combinatory stem, three solely word forms, and two being both. It also fails to capture some inflected forms. However, five of the forms are basic inflected verb forms, and the system also describes almost all extended forms in a consistent way.
Japanese verbs are classified into eight conjugation classes, each characterized by different patterns of inflected forms. Three of these classes are grouped as consonant bases:
- Yodan (quadrigrade)
- This class of regular consonant-base verbs includes approximately 75% of verbs. The class is so named because the inflections in later forms of Japanese span four rows of a kana table, corresponding to four vowels. However, in Old Japanese five different vowels are involved. These bases are almost all of the form (C)VC-, with the final consonant limited to p, t, k, b, g, m, s or r.
- Na-hen (n-irregular)
- The three n-base verbs form a class of their own: sin- 'die', -in- 'depart' and the auxiliary -(i)n- expressing completion of an action. They are often described as a "hybrid" conjugation, because the adnominal and exclamatory forms follow a similar pattern to vowel-base verbs.
- Ra-hen (r-irregular)
- The irregular r-base verbs are ar- 'be, exist' and other verbs incorporating it, as well as wor- 'sit', which became the existential verb or- in later forms of Japanese.
The distinctions between i1 and i2 and between e1 and e2 are lost after s, z, t, d, n, y, r and w.
There are five vowel-base conjugation classes:
- Shimo nidan (lower bigrade or e-bigrade)
- The largest regular vowel-base class comprises bases ending in e2, and includes approximately 20% of verbs.
- Kami nidan (upper bigrade or i-bigrade)
- This class of bases ending in i2 contains about 30 verbs.
- Kami ichidan (upper monograde or i-monograde)
- This class contains about 10 verbs of the form (C)ii-. Some monosyllabic upper bigrade verbs had already shifted to this class by the Old Japanese period, and the rest followed in Early Middle Japanese.
- Ka-hen (k-irregular)
- This class consists of the single verb ko2- 'come'.
- Sa-hen (s-irregular)
- This class consists of the single verb se- 'do'.
Early Middle Japanese also had a Shimo ichidan (lower monograde or e-monograde) category consisting of a single verb kwe- 'kick', which reflects the Old Japanese lower bigrade verb kuwe-.
The bigrade verbs seem to belong to a later layer than the consonant-base verbs. Many e-bigrade verbs are transitive or intransitive counterparts of consonant-stem verbs. In contrast, i-bigrade verbs tend to be intransitive. Some bigrade bases also appear to reflect pre-Old-Japanese adjectives with vowel stems combined with an inchoative *-i suffix:
- *-a-i > -e2, e.g. ake2- 'redden, lighten' vs aka 'red'.
- *-u-i > -i2, e.g. sabi2- 'get desolate, fade' vs sabu- 'lonely'.
- *-ə-i > -i2, e.g. opi2- 'get big, grow' vs opo- 'big'.
This section needs additional citations for verification. (November 2014) (Learn how and when to remove this template message)
The regular adjective is sub-classified into two types: those where the adverbial form (連用形) ends in -ku and those that end in -siku. This creates two different types of conjugations:
The -kar- and -sikar- forms are derived from the adverbial conjugation (-ku or -siku) suffixed with verb ar- "be, exists". The conjugation yields to the R-irregular conjugation of ar-. As Old Japanese avoids vowel clusters, the resulting -ua- is reduced to -a-.
The adjectival noun has a single conjugation:
- 230 azuma uta 'eastern songs' in volume 14 of the Man'yōshū,
- 93 sakimori uta 'borderguard songs' in volume 20 of the Man'yōshū, and
- 9 songs in the Hitachi fudoki (714–718).
They record Eastern Old Japanese dialects, with features such as:
- There is no type A/B distinction on front vowels i and e, though o1 and o2 are distinguished.
- Pre-Old Japanese *ia yielded a in the east, where Central Old Japanese has e1.
- The adnominal form of consonant-base verbs ended in -o1, where Central Old Japanese has -u as in the conclusive form. A similar difference is preserved in Ryukyuan languages, suggesting that Central Old Japanese had innovated by merging these endings.
- The imperative form of vowel-base verbs attached -ro2, instead of the -yo2 used in Central Old Japanese.
- There are a group of distinctive negative auxiliaries. However, they do not seem to be the source of the different negatives in modern eastern and western Japanese dialects.
- Described as "The ancestor of modern Japanese. 7th–10th centuries AD." The more usual date for the change from Old Japanese to Middle Japanese is ca. 800 (end of the Nara era).
- Readings are given in Baxter's transcription for Middle Chinese, omitting marking of tones, which are not relevant here.
- Shibatani 1990, p. 119.
- Miyake 2003, p. 1.
- Miyake 2003, p. 17.
- Frellesvig 2010, p. 24.
- Miyake 2003, pp. 19–20.
- Bentley 2001, p. 6.
- Miyake 2003, pp. 5–8.
- Miyake 2003, p. 10.
- Seeley 1991, pp. 16–25.
- Miyake 2003, p. 12.
- Miyake 2003, p. 66.
- Miyake 2003, pp. 8–9.
- Seeley 1991, pp. 25–31.
- Shibatani 1990, p. 126.
- Seeley 1991, pp. 41–49.
- Miyake 2003, pp. 18–20, 28–40.
- Miyake 2003, pp. 1, 18, 22.
- Frellesvig 2010, p. 19.
- Seeley 1991, pp. 49–53.
- Miyake 2003, pp. 20, 24–27.
- Frellesvig 2010, pp. 17–20.
- Miyake 2003, pp. 49–51.
- Frellesvig 2010, pp. 26–27.
- Frellesvig 2010, pp. 28–29.
- Miyake 2003, p. 51.
- Frellesvig 2010, p. 30.
- Miyake 2003, p. 84.
- Frellesvig 2010, p. 26.
- Miyake 2003, p. 62.
- Frellesvig 2010, p. 32.
- Miyake 2003, p. 2.
- Miyake 2003, pp. 54–55, 63–64.
- Miyake 2003, pp. 64–65.
- Frellesvig 2010, p. 43.
- Frellesvig 2010, p. 39.
- Frellesvig 2010, p. 44.
- Miyake 2003, pp. 198–203.
- Miyake 2003, pp. 207–211.
- Miyake 2003, p. 55.
- Miyake 2003, pp. 55–57.
- Miyake 2003, pp. 80–81.
- Miyake 2003, p. 81.
- Frellesvig 2010, p. 46.
- Miyake 2003, p. 80.
- Frellesvig 2010, p. 45.
- Shibatani 1990, p. 134.
- Frellesvig 2010, p. 48.
- Erickson 2003, p. 499.
- Shibatani 1990, p. 133.
- Erickson 2003, pp. 498–499.
- Erickson 2003, p. 498.
- Frellesvig 2010, pp. 45–47.
- Unger 2000, p. 661.
- Frellesvig 2010, pp. 47–48.
- Miyake 2003, p. 196.
- Miyake 2003, pp. 75–76.
- Miyake 2003, pp. 183, 186.
- Shibatani 1990, p. 194.
- Miyake 2003, p. 74.
- Miyake 2003, pp. 71, 164–166.
- Miyake 2003, p. 73.
- Frellesvig 2010, pp. 42–43.
- Miyake 2003, pp. 71–73.
- Vovin 2010, pp. 36–44.
- Unger 2000, p. 666.
- Miyake 2003, pp. 68–71.
- Unger 2000, p. 662.
- Frellesvig 2010, pp. 39–40.
- Miyake 2003, pp. 37–39.
- Shibatani 1990, pp. 122–123.
- Frellesvig 2010, pp. 136–137.
- Frellesvig 2010, p. 138.
- Frellesvig 2010, p. 136.
- Frellesvig 2010, pp. 138–139.
- Frellesvig 2010, pp. 139–140.
- Frellesvig 2010, p. 141.
- Frellesvig 2010, pp. 140, 246–247.
- Shibatani 1990, p. 123.
- Frellesvig 2010, p. 53.
- Frellesvig 2010, p. 59.
- Frellesvig 2010, pp. 114–118.
- Frellesvig 2010, pp. 111–112.
- Unger 2000, p. 665.
- Frellesvig 2010, pp. 56–57.
- Frellesvig 2010, pp. 109–111.
- Frellesvig 2010, pp. 123–124, 133.
- Shibatani (1990), pp. 195, 207, 223–224.
- Frellesvig 2010, pp. 54–55.
- Frellesvig 2010, p. 133.
- Frellesvig 2010, p. 55.
- Frellesvig 2010, pp. 112–113.
- Frellesvig 2010, pp. 116–118.
- Frellesvig 2010, p. 96.
- Frellesvig 2010, p. 115.
- Frellesvig 2010, p. 97.
- Frellesvig 2010, p. 105.
- Frellesvig 2010, pp. 101–103.
- Frellesvig 2010, pp. 54, 114.
- Frellesvig 2010, p. 106.
- Frellesvig 2010, pp. 107–108.
- Frellesvig 2010, pp. 227–228.
- Yamaguchi et al. 1997, p. 18.
- Kondō, Tsukimoto & Sugiura 2005, p. 41.
- Omodaka 1967, pp. 37–38.
- Frellesvig 2010, p. 120.
- Frellesvig 2010, pp. 118–119.
- Whitman 2008, p. 164.
- Frellesvig 2010, p. 119.
- Whitman 2008, p. 165.
- Bentley 2012, p. 197.
- Vovin 2005.
- Miyake 2003, p. 159.
- Frellesvig 2010, pp. 23–24, 151.
- Kupchik 2011.
- Frellesvig 2010, p. 152.
- Frellesvig 2010, pp. 152–153.
- Bentley 2012, p. 189.
- Frellesvig 2010, p. 153.
- Bentley, John R. (2001). A Descriptive Grammar of Early Old Japanese Prose. BRILL. ISBN 978-90-04-12308-3.
- ——— (2012). "Old Japanese". In Tranter, Nicolas. The Languages of Japan and Korea. Routledge. pp. 189–211. ISBN 978-1-136-44658-0.
- Erickson, Blaine (2003). "Old Japanese and Proto-Japonic word structure" (PDF). In Vovin, Alexander; Osada, Toshiki. Nihongo keitōron no genzai 日本語系統論の現在 [Perspectives on the Origins of the Japanese Language]. Kyoto: International Research Center for Japanese Studies. pp. 493–510. ISBN 978-4-901558-17-4.
- Frellesvig, Bjarke (2010). A History of the Japanese Language. Cambridge: Cambridge University Press. ISBN 978-0-521-65320-6.
- Kondō, Yasuhiro; Tsukimoto, Masayuki; Sugiura, Katsumi (2005). Nihongo no Rekishi [A history of the Japanese language] (in Japanese). Tokyo: Hōsō Daigaku Kyōiku Shinkōkai. ISBN 978-4-595-30547-4.
- Kupchik, John E. (2011). A grammar of the eastern old Japanese dialects (PhD thesis). University of Hawai'i.
- Miyake, Marc Hideo (2003). Old Japanese: A Phonetic Reconstruction. London; New York: RoutledgeCurzon. ISBN 978-0-415-30575-4.
- Omodaka, Hisataka, ed. (1967). Jidaibetsu Kokugo Daijiten: Jōdaihen [Comprehensive dictionary of Japanese by historical period: ancient edition] (in Japanese). Tokyo: Sanseidō. ISBN 978-4-385-13237-2.
- Seeley, Christopher (1991). A History of Writing in Japan. Leiden: BRILL. ISBN 978-90-04-09081-1.
- Shibatani, Masayoshi (1990). The Languages of Japan. Cambridge: Cambridge University Press. ISBN 978-0-521-36918-3.
- Unger, J. Marshall (2000). "Reconciling Comparative and Internal Reconstruction: The Case of Old Japanese /ti, ri, ni/". Language. 76 (3): 655–681. doi:10.2307/417138. JSTOR 417138.
- Vovin, Alexander (2005). A Descriptive and Comparative Grammar of Western Old Japanese. Part One: Sources, Script and Phonology, Lexicon, Nominals. Folkestone, Kent: Global Oriental. ISBN 978-1-901903-14-0.
- ——— (2010). Korea-Japonica: A Re-Evaluation of a Common Genetic Origin. University of Hawaii Press. ISBN 978-0-8248-3278-0.
- Whitman, John (2008). "The source of the bigrade conjugation and stem shape in pre-Old-Japanese". In Frellesvig, Bjarne; Whitman, John. Proto-Japanese: Issues and Prospects. John Benjamins. pp. 160–173. ISBN 978-90-272-4809-1.
- Yamaguchi, Akiho; Suzuki, Hideo; Sakanashi, Ryūzō; Tsukimoto, Masayuki (1997). Nihongo no Rekishi [A history of the Japanese language] (in Japanese). Tōkyō: Tōkyō Daigaku Shuppankai. ISBN 978-4-13-082004-2.
- Frellesvig, Bjarne; Whitman, John, eds. (2008). Proto-Japanese: Issues and Prospects. John Benjamins. ISBN 978-90-272-4809-1.
- Pellard, Thomas (2010). "Bjarke Frellesvig & John Whitman (2008) Proto-Japanese : Issues and prospects". Cahiers de Linguistique – Asie Orientale. 39 (1): 95–114. doi:10.1163/1960602810x00089.
- Hayata, Teruhiro (2000). "The liquid and stem-final vowel alternations of verbs in ancient Japanese". Gengo Kenkyu (118): 5–27. doi:10.11435/gengo1939.2000.118_5.
- Martin, Samuel E. (1987). The Japanese Language Through Time. New Haven: Yale University Press. ISBN 978-0-300-03729-6.
- Ōno, Susumu (2000). Nihongo no Keisei 日本語の形成 [The Formation of the Japanese Language] (in Japanese). Tokyo: Iwanami Shoten. ISBN 978-4-00-001758-9.
- Tōdō, Akiyasu; Kanō, Yoshimitsu (2005). Gakken Shin Kan-Wa Daijiten 学研新漢和大字典 [Gakken new Chinese-Japanese character dictionary] (in Japanese). Tokyo: Gakushū Kenkyūsha. ISBN 978-4-05-300082-8.
- Vovin, Alexander (2009). A Descriptive and Comparative Grammar of Western Old Japanese. Part Two: Adjectives, Verbs, Adverbs, Conjunctions, Particles, Postpositions. Folkestone, Kent: Global Oriental. ISBN 978-1-905246-82-3.
- Yuko, Yanagida (2012). "The Syntactic Reconstruction of Alignment and Word Order: The Case of Old Japanese". Historical Linguistics 2009: Selected papers from the 19th International Conference on Historical Linguistics. Historical Linguistics: Current Issues in Linguistic Theory. 320. John Benjamins. pp. 107–128. doi:10.1075/cilt.320.06yan. ISBN 978-90-272-7480-9.