Latin declension is the set of patterns according to which Latin words are declined, or have their endings altered to show grammatical case, number and gender. Nouns, pronouns, and adjectives are declined (verbs are conjugated), and a given pattern is called a declension. There are five declensions, which are numbered and grouped by ending and grammatical gender. Each noun follows one of the five declensions, but some irregular nouns have exceptions.
Adjectives are of two kinds: those like bonus, bona, bonum 'good' use first-declension endings for the feminine, and second-declension for masculine and neuter. Other adjectives such as celer, celeris, celere belong to the third declension. There are no fourth- or fifth-declension adjectives.
Pronouns are also of two kinds, the personal pronouns such as ego 'I' and tū 'you (sg.)', which have their own irregular declension, and the third-person pronouns such as hic 'this' and ille 'that' which can generally be used either as pronouns or adjectivally. These latter decline in a similar way to the first and second noun declensions, but there are differences; for example the genitive singular ends in -īus or -ius instead of -ī or -ae.
The cardinal numbers ūnus 'one', duo 'two', and trēs 'three' also have their own declensions (ūnus has genitive -īus like a pronoun), and there are also numeral adjectives such as bīnī 'a pair, two each', which decline like ordinary adjectives.
A complete Latin noun declension consists of up to seven grammatical cases: nominative, vocative, accusative, genitive, dative, ablative and locative. However, the locative is limited to few nouns: generally names of cities, small islands and a few other words.
The case names are often abbreviated to the first three letters.
Order of cases
The grammarian Aelius Donatus (4th century AD), whose work was used as standard throughout the Middle Ages, placed the cases in this order:
- casus sunt sex: nominativus, genetivus, dativus, accusativus, vocativus, ablativus.
- "There are six cases: nominative, genitive, dative, accusative, vocative and ablative."
This order was based on the order used by earlier Greek grammarians, with the addition of the ablative, which does not exist in Greek. The names of the cases also were mostly translated from the Greek terms, such as accusativus from the Greek αἰτιατική.
The traditional order was formerly used in England, for example in The School and University Eton Latin Grammar (1861). and it is also still used in Germany and most European countries. Gildersleeve and Lodge's Latin Grammar of 1895, also follows this order. More recent American grammars, such as Allen and Greenough's New Latin Grammar (1903) and Wheelock's Latin (first published in 1956), use this order but with the vocative at the end.
However, in Britain and countries influenced by Britain, the Latin cases are usually given in the following order: nominative, vocative, accusative, genitive, dative, ablative. This order was first introduced in Benjamin Hall Kennedy's Latin Primer (1866), with the aim of making tables of declensions easier to recite and memorise. It is also used in France and Belgium.
Syncretism, where one form in a paradigm shares the ending of another form in the paradigm, is common in Latin. The following are the most notable patterns of syncretism:
- For pure Latin neuter nouns, the nominative singular, vocative singular, and accusative singular are identical; and the nominative plural, vocative plural, and accusative plural all end in -a. (Both of these features are inherited from Proto-Indo-European, and so no actual syncretism is known to have happened in the historical sense, since these cases of these nouns are not known to have ever been different in the first place.)
- The vocative form is always the same as the nominative in the plural, and usually the same as the nominative in the singular except for second-declension masculine nouns ending in -us and a few nouns of Greek origin. For example, the vocative of the first-declension Aenēās is Aenēā.
- The genitive singular is the same as the nominative plural in first-, second-, and fourth-declension masculine and feminine pure Latin nouns.
- The dative singular is the same as the genitive singular in first- and fifth-declension pure Latin nouns.
- The dative is always the same as the ablative in the singular in the second declension, the third-declension full i-stems (i.e. neuter i-stems, adjectives), and fourth-declension neuters.
- The dative, ablative, and locative are always identical in the plural.
- The locative is identical to the ablative in the fourth and fifth declensions.
History of cases
Old Latin had essentially two patterns of endings. One pattern was shared by the first and second declensions, which derived from the Proto-Indo-European thematic declension. The other pattern was used by the third, fourth and fifth declensions, and derived from the athematic PIE declension.
There are two principal parts for Latin nouns: the nominative singular and the genitive singular. Each declension can be unequivocally identified by the ending of the genitive singular (-ae, -i, -is, -ūs, -ei). The stem of the noun can be identified by the form of the genitive singular as well.
There are five declensions for Latin nouns:
First declension (a stems)
Nouns of this declension usually end in -a in the nominative singular and are mostly feminine, e.g. via, viae f. ('road') and aqua, aquae f. ('water'). There is a small class of masculine exceptions generally referring to occupations, e.g. poēta, poētae m. ('poet'), agricola, agricolae m. ('farmer') and nauta, nautae m. ('sailor').
|First declension paradigm|
First declension Greek nouns
The first declension also includes three types of Greek loanwords, derived from Ancient Greek's alpha declension. They are declined irregularly in the singular, but sometimes treated as native Latin nouns, e.g. nominative athlēta ('athlete') instead of the original athlētēs. Archaic (Homeric) first declension Greek nouns and adjectives had been formed in exactly the same way as in Latin: nephelēgeréta Zeus ('Zeus the cloud-gatherer') had in classical Greek become nephelēgerétēs.
For full paradigm tables and more detailed information, see the Wiktionary appendix First declension.
Second declension (o stems)
The second declension is a large group of nouns consisting of mostly masculine nouns like equus, equī ('horse') and puer, puerī ('boy') and neuter nouns like castellum, castellī ('fort'). There are several small groups of feminine exceptions, including names of gemstones, plants, trees, and some towns and cities.
In the nominative singular, most masculine nouns consist of the stem and the ending -us, although some end in -er, which is not necessarily attached to the complete stem. Neuter nouns generally have a nominative singular consisting of the stem and the ending -um. However, every second-declension noun has the ending -ī attached as a suffix to the root of the noun in the genitive singular form. The predominant letter in the ending forms of this declension is o.
|Second declension paradigm|
Second-declension -ius and -ium nouns
Nouns ending in -ius and -ium have a genitive singular in -ī in earlier Latin, which was regularized to -iī in the later language. Masculine nouns in -ius have a vocative singular in -ī at all stages. These forms in -ī are stressed on the same syllable as the nominative singular, sometimes in violation of the usual Latin stress rule. For example, the genitive and vocative singular Vergilī (from Vergilius) is pronounced Vergílī, with stress on the penult, even though it is short. In Old Latin, however, the vocative was declined regularly, using -ie instead, e.g. fīlie "[O] son", archaic vocative of fīlius.
There is no contraction of -iī(s) in plural forms and in the locative.
aid, help n.
In the older language, nouns ending with -vus, -quus and -vum take o rather than u in the nominative and accusative singular. For example, servus, servī ('slave') could be servos, accusative servom.
Second-declension -r nouns
Some masculine nouns of the second declension end in -er or -ir in the nominative singular. The declension of these nouns is identical to that of the regular second declension, except for the lack of suffix in the nominative and vocative singular.
Some (but not all) nouns in -er drop the e genitive and other cases. For example, socer, socerī ('father-in-law') keeps its e. However, the noun magister, magistrī ('(school)master') drops its e in the genitive singular.
For declension tables of second-declension nouns, see the corresponding Wiktionary appendix.
Second-declension Greek nouns
The second declension contains two types of masculine Greek nouns and one form of neuter Greek noun. These nouns are irregular only in the singular, as are their first-declension counterparts. Greek nouns in the second declension are derived from the Omicron declension.
Some Greek nouns may also be declined as normal Latin nouns. For example, theātron can appear as theātrum.
In poetry, -um may substitute -ōrum as the genitive plural ending.
The Latin word vīrus (the ī indicates a long i) means "1. slimy liquid, slime; 2. poison, venom", denoting the venom of a snake. This Latin word is probably related to the Greek ῑ̓ός (ios) meaning "venom" or "rust" and the Sanskrit word विष viṣa meaning "toxic, poison".
poison, venom, virus n.
- antique, heteroclitic: vīrus
The third declension is the largest group of nouns. The nominative singular of these nouns may end in -a, -e, -ī, -ō, -y, -c, -l, -n, -r, -s, -t, or -x. This group of nouns includes masculine, neuter, and feminine nouns.
The stem of a consonant-stem noun may be found from the genitive case by removing the ending -is. For example, the stem of pāx, pācis f. 'peace' is pāc-, the stem of flūmen, flūminis n. 'river' is flūmin-, and the stem of flōs, flōris m. 'flower' is flōr-.
Masculine, feminine and neuter nouns often have their own special nominative singular endings. For instance, many masculine nouns end in -or (amor, amōris, 'love'). Many feminine nouns end in -īx (phoenīx, phoenīcis, 'phoenix'), and many neuter nouns end in -us with an r stem in the oblique cases (onus, oneris 'burden'; tempus, temporis 'time').
|Third declension paradigm|
- The nominative and accusative of neuter nouns are always identical.
Third declension i-stem and mixed nouns
The third declension also has a set of nouns that are declined differently. They are called i-stems. i-stems are broken into two subcategories: pure and mixed. Pure i-stems are indicated by special neuter endings. Mixed i-stems are indicated by the double consonant rule. Stems indicated by the parisyllabic rule are usually mixed, occasionally pure.
- Masculine and feminine
- Parisyllabic rule: Some masculine and feminine third-declension i-stem nouns have the same number of syllables in the genitive as they do in the nominative. For example: nāvis, nāvis ('ship'); nūbēs, nūbis ('cloud'). The nominative ends in -is or -ēs.
- Double consonant rule: The rest of the masculine and feminine third-declension i-stem nouns have two consonants before the -is in the genitive singular. For example: pars, partis ('part').
- Special neuter ending: Neuter third-declension i-stems have no rule. However, all of them end in -al, -ar or -e. For example: animal, animālis ('animal'); cochlear, cochleāris ('spoon'); mare, maris ('sea').
The mixed declension is distinguished from the consonant type only by having -ium in the genitive plural (and occasionally -īs in the accusative plural). The pure declension is characterized by having -ī in the ablative singular, -ium in the genitive plural, -ia in the nominative and accusative plural neuter, and -im in the accusative singular masculine and feminine (however, adjectives have -em).
The accusative singular ending -im is found only in a few words: always in tussis 'cough', sitis 'thirst', Tiberis 'River Tiber'; usually in secūris 'axe', turris 'tower'; occasionally in nāvis 'ship'. Most nouns, however, have accusative singular -em.
The ablative singular -ī is found in nouns which have -im, and also, optionally, in some other nouns, e.g. in ignī or in igne 'in the fire'.
|Third declension paradigm|
|Third declension paradigm|
tower f. (pure)
part, piece f. (mixed)
animal, living being n. (pure)
|Parisyllabic rule||Double consonant rule||Special neuter ending|
The rules for determining i-stems from non-i-stems and mixed i-stems are guidelines rather than rules: many words that might be expected to be i-stems according to the parisyllabic rule actually are not, such as canis ('dog') or iuvenis ('youth'), which have genitive plural canum 'of dogs' and iuvenum 'of young men'. Likewise, pater ('father'), māter ('mother'), frāter ('brother'), and parēns ('parent') violate the double-consonant rule. This fluidity even in Roman times resulted in much more uncertainty in Medieval Latin.
In the third declension, there are four irregular nouns.
force, power f.
swine, pig, hog m.f.
ox, bullock m.f.
|Iuppiter, Iovis |
- Here ō or ū come from Old Latin ou. Thus bō-/bū- and Iū- before consonant endings are alternate developments of the bov- and Iov- before vowel endings. — The double pp in the preferred form Iu-ppiter "Father Jove" is an alternate way of marking the length of the u in the etymological form Iū-piter (see footnote in Jupiter (mythology)). i is weakened from a in pater (Allen and Greenough, sect. 79 b).
- Genitive and dative cases are seldom used.
Fourth declension (u stems)
The fourth declension is a group of nouns consisting of mostly masculine words such as fluctus, fluctūs m. ('wave') and portus, portūs m. ('port') with a few feminine exceptions, including manus, manūs f. ('hand'). The fourth declension also includes several neuter nouns including genū, genūs n. ('knee'). Each noun has the ending -ūs as a suffix attached to the root of the noun in the genitive singular form. The predominant letter in the ending forms of this declension is u, but the declension is otherwise very similar to the third-declension i stems.
|Fourth declension paradigm|
|-us ending nouns||-ū ending nouns|
port, haven, harbor m.
In the dative and ablative plural, -ibus is sometimes replaced with -ubus. This is so for only a few nouns, such as artūs pl., ('limbs').
Domus ('house, dwelling, building, home, native place, family, household, race') is an irregular noun, mixing fourth and second declension nouns at the same time (especially in literature). However, in practice, it is generally declined as a regular -us stem fourth declension noun (except by the ablative singular and accusative plural, using -ō and -ōs instead).
|domus, domūs/domī f.|
|All possible declensions|
|domus, domūs f.|
|Most common paradigm|
Fifth declension (e stems)
The fifth declension is a small group of nouns consisting of mostly feminine nouns like rēs, reī f. ('affair, matter, thing') and diēs, diēī m. ('day'; but f. in names of days). Each noun has either the ending -ēī or -eī as a suffix attached to the root of the noun in the genitive singular form.
|Fifth declension paradigm|
|-iēs ending nouns||-ēs ending nouns|
day m., f.
Nouns ending in -iēs have long ēī in the dative and genitive, while nouns ending in a consonant + -ēs have short eī in these cases.
The locative ending of the fifth declension was -ē (singular only), identical to the ablative singular, as in hodiē ('today').
The first and second persons are irregular, and both pronouns are indeclinable for gender; and the third person reflexive pronoun sē, suī always refers back to the subject, regardless of whether the subject is singular or plural.
|First Person||Second Person||Third Person|
himself, herself, itself,
The genitive forms meī, tuī, nostrī, vestrī, suī are used as complements in certain grammatical constructions, whereas nostrum, vestrum are used with a partitive meaning ('[one] of us', '[one] of you'). To express possession, the possessive pronouns (essentially adjectives) meus, tuus, noster, vester are used, declined in the first and second declensions to agree in number and case with the thing possessed, e.g. pater meus 'my father', māter mea 'my mother'. The vocative singular masculine of meus is mī: mī Attice 'my dear Atticus'.
Possessive pronouns' declensions
|meus, mea, meum|
|tuus, tua, tuum|
your, yours (for singular possessor)
|suus, sua, suum|
his, her, its, theirs (reflexive)
|noster, nostra, nostrum|
The possessive adjective vester has an archaic variant, voster; similar to noster.
|vester, vestra, vestrum|
voster, vostra, vostrum
your, yours (for plural possessor)
Usually, to show the ablative of accompaniment, cum would be added to the ablative form. However, with personal pronouns (first and second person), the reflexive and the interrogative, -cum is added onto the end of the ablative form. That is: mēcum 'with me', nōbīscum 'with us', tēcum 'with you', vōbīscum, sēcum and quōcum (sometimes quīcum).
In accusative case, the forms mēmē and tētē exist as emphatic, but they are not widely used.
When 'his' or 'her' refers to someone else, not the subject, the genitive pronoun eius (as well as eōrum and eārum) 'of him' is used instead of suus:
When one sentence is embedded inside another with a different subject, sē and suus can refer to either subject:
- Patrēs conscrīptī ... lēgātōs in Bīthȳniam miserunt quī ab rēge peterent, nē inimīcissimum suum secum haberet sibique dēderet. (Nepos)
- "The senators ... sent ambassadors to Bithynia, who were to ask the king not to keep their greatest enemy with him but hand him over to them."
For the third-person pronoun is 'he', see below.
Demonstrative pronouns and adjectives
Relative, demonstrative and indefinite pronouns are generally declined like first and second declension adjectives, with the following differences:
- the nominatives are often irregular
- the genitive singular ends in -īus rather than -ae or -ī.
- the dative singular ends in -ī: rather than -ae or -ō.
These differences characterize the pronominal declension, and a few special adjectives (tōtus 'whole', sōlus 'alone', ūnus 'one', nūllus 'no', alius 'another', alter 'another [of two]', etc.) are also declined according to this pattern.
All demonstrative, relative, and indefinite pronouns in Latin can also be used adjectivally, with some small differences; for example in the interrogative pronoun, quis 'who?' and quid 'what?' are usually used for the pronominal form, quī and quod 'which?' for the adjectival form.
Third person pronoun
|is, ea, id|
he, she, it
This pronoun is also often used adjectivally, e.g. is homo 'that man', ea pecunia 'that money'. It has no possessive adjective; the genitive is used instead: pater eius 'his/her father'; pater eōrum 'their father'.
Declension of īdem
|īdem, eadem, idem|
the same, same as
Other demonstrative pronouns
|hic, haec, hoc
this, this one (proximal)
|ille, illa, illud
that, that one (distal)
|iste, ista, istud|
that of yours (medial)
Similar in declension is alius, alia, aliud 'another'.
|ipse, ipsa, ipsum|
himself, herself, itself
The interrogative pronouns are used strictly for asking questions. They are distinct from the relative pronoun and the interrogative adjective (which is declined like the relative pronoun). Interrogative pronouns rarely occur in the plural. The plural interrogative pronouns are the same as the plural relative pronouns.
|quī, quae, quod|
who, which, that
First- and second-declension adjectives
First- and second-declension adjectives are inflected in the masculine, the feminine and the neuter; the masculine form typically ends in -us (although some end in -er, see below), the feminine form ends in -a, and the neuter form ends in -um. Therefore, some adjectives are given like altus, alta, altum.
Adjectives ending -ius use the vocative -ie (ēbrie, "[O] drunk man", vocative of ēbrius), just as in Old Latin all -ius nouns did (fīlie, "[O] son", archaic vocative of fīlius).
|altus, alta, altum|
high, long, tall
First- and second-declension -r adjectives
Some first- and second-declension adjectives' masculine forms end in -er. As with second-declension -r nouns, some adjectives retain the e throughout inflection, and some omit it. Sacer, sacra, sacrum omits its e while miser, misera, miserum keeps it.
|miser, misera, miserum|
sad, poor, unhappy
|sacer, sacra, sacrum|
First and second declension pronominal adjectives
Nine first and second declension pronominal adjectives are irregular in the genitive and the dative in all genders. They can be remembered by using the mnemonic acronym ūnus nauta. They are:
- ūllus, ūlla, ūllum 'any';
- nūllus, nūlla, nūllum 'no, none';
- uter, utra, utrum 'which [of two], either';
- sōlus, sōla, sōlum 'sole, alone';
- neuter, neutra, neutrum 'neither';
- alius, alia, aliud 'another' (the genitive singular alīus is often replaced by alterīus or by aliēnus 'of another');
- ūnus, ūna, ūnum 'one';
- tōtus, tōta, tōtum 'whole';
- alter, altera, alterum 'other [of two]'.
|ūllus, ūlla, ūllum|
Third-declension adjectives are normally declined like third-declension i-stem nouns, except for the fact they usually have -ī rather than -e in the ablative singular (unlike i-stem nouns, in which only pure i-stems have -ī). Some adjectives, however, like the one-ending vetus, veteris ('old, aged'), have -e in the ablative singular, -um in the genitive plural, and -a in the nominative and accusative neuter plural.
Third-declension adjectives with one ending
These have a single nominative ending for all genders, although as usual the endings for the other cases vary. As with nouns, a genitive is given for the purpose of showing the inflection.
terrible, mean, cruel
Third-declension adjectives with two endings
Third-declension adjectives that have two endings have one form for the masculine and feminine, and a separate form for the neuter. The ending for the masculine and feminine is -is, and the ending for the neuter is -e. It is not necessary to give the genitive, as it is the same as the nominative masculine singular.
Third-declension adjectives with three endings
Third-declension adjectives with three endings have three separate nominative forms for all three genders. Like third and second declension -r nouns, the masculine ends in -er. The feminine ends in -ris, and the neuter ends in -re. The genitive is the same as the nominative feminine singular.
|celer, celeris, celere|
swift, rapid, brash
|alacer, alacris, alacre|
lively, jovial, animated
Comparative and superlative forms of adjectives
As in English, adjectives have superlative and comparative forms. For regular first and second declension and third declension adjectives with one or two endings, the comparative is formed by adding -ior for the masculine and feminine, and -ius for the neuter to the stem. The genitives for both are formed by adding -iōris. Therefore, they are declined in the third declension, but they are not declined as i-stems. Superlatives are formed by adding -issimus, -issima, -issimum to the stem and are thus declined like first and second declension adjectives.
General pattern for comparatives
higher, deeper (comparative of altus)
|altissimus, altissima, altissimum|
highest, deepest (superlative of altus)
Comparatives and superlatives with normal endings
|clārus, clāra, clārum ('clear, bright, famous')||clārior, clārius||clārissimus, clārissima, clārissimum|
|frīgidus, frīgida, frīgidum ('cold, chilly')||frīgidior, frīgidius||frīgidissimus, frīgidissima, frīgidissimum|
|pugnāx, pugnāx (pugnācis) ('pugnacious')||pugnācior, pugnācius||pugnācissimus, pugnācissima, pugnācissimum|
|benevolēns, benevolēns (benevolentis) ('kind, benevolent')||benevolentior, benevolentius||benevolentissimus, benevolentissima, benevolentissium|
|fortis, forte ('strong, robust')||fortior, fortius||fortissimus, fortissima, fortissimum|
|aequālis, aequāle ('equal, even')||aequālior, aequālius||aequālissimus, aequālissima, aequālissimum|
Comparatives and superlatives of -er adjectives
Adjectives (in the first and second as well as third declensions) that have masculine nominative singular forms ending in -er are slightly different. As with normal adjectives, the comparative is formed by adding -ior to the stem, but for the superlative, -rimus is added to the nominative masculine singular.
|pulcher, pulchra, pulchrum ('pretty, beautiful')||pulchrior, pulchrius||pulcherrimus, pulcherrima, pulcherrimum|
|sacer, sacra, sacrum ('sacred, holy')||sacrior, sacrius||sacerrimus, sacerrima, sacerrimum|
|tener, tenera, tenerum ('delicate, tender')||tenerior, tenerius||tenerrimus, tenerrima, tenerrimum|
|ācer, ācris, ācre ('valliant, fierce')||ācrior, ācrius||ācerrimus, ācerrima, ācerrimum|
|celeber, celebris, celebre ('celebrated, famous')||celebrior, celebrius||celeberrimus, celeberrima, celeberrimum|
|celer, celeris, celere ('quick, fast')||celerior, celerius||celerrimus, celerrima, celerrimum|
Comparatives and superlatives of -lis adjectives
Some third declension adjectives with two endings in -lis in the masculine–feminine nominative singular have irregular superlative forms. The following are the only adjectives that do.
|facilis, facile ('easy')||facilior, facilius||facillimus, facillima, facillimum|
|difficilis, difficile ('hard, difficult')||difficilior, difficilius||difficillimus, difficillima, difficillimum|
|similis, simile ('similar, like)||similior, similius||simillimus, simillima, simillimum|
|dissimilis, dissimile ('unlike, dissimilar')||dissimilior, dissimilius||dissimillimus, dissimillima, dissimillimum|
|gracilis, gracile ('slender, slim')||gracilior, gracilius||gracillimus, gracillima, gracillimum|
|humilis, humile ('low, humble')||humilior, humilius||humillimus, humillima, humillimum|
Comparatives and superlatives of -eus/-ius adjectives
First and second declension adjectives that end in -eus or -ius are unusual in that they do not form the comparative and superlative by taking endings at all. Instead, magis ('more') and maximē ('most'), the comparative and superlative degrees of magnoperē ('much, greatly'), respectively, are used.
Many adjectives in -uus, except those in -quus or -guus, also follow this rule.
|idōneus, idōnea, idōneum ('suitable, fitting, proper')||magis idōneus||maximē idōneus|
|sōlitārius, sōlitāria, sōlitārium ('solitary, lonely')||magis sōlitārius||maximē sōlitārius|
|ebrius, ebria, ebrium ('drunk')||magis ebrius||maximē ebrius|
|meritōrius, meritōria, meritōrium ('meritorious')||magis meritōrius||maximē meritōrius|
|grāmineus, grāminea, grāmineum ('grassy')||magis grāmineus||maximē grāmineus|
|bellātōrius, bellātōria, bellātōrium ('warlike, bellicose')||magis bellātōrius||maximē bellātōrius|
|arduus, ardua, arduum ('lofty, steep')||magis arduus||maximē arduus|
Irregular comparatives and superlatives
As in most languages, Latin has adjectives that have irregular comparatives and superlatives.
Declension of numerals
There are several different kinds of numeral words in Latin: the two most common are cardinal numerals and ordinal numerals. There are also several more rare numerals, e.g., distributive numerals and adverbial numerals.
All cardinal numerals are indeclinable, except ūnus ('one'), duo ('two'), trēs ('three'), plural hundreds ducentī ('two hundred'), trecentī ('three hundred') etc., and mīlle ('thousand'), which have cases and genders like adjectives. Ūnus, ūna, ūnum is declined like a first- and second-declension pronoun with -īus or -ius in the genitive, and -ī in the dative. Duo is declined irregularly, trēs is declined like a third-declension plural adjective, -centī ('hundred') numerals decline like first- and second-declension adjectives, and mīlle is invariable in the singular and declined like a third-declension i-stem neuter noun in the plural:
The plural endings for ūnus are used with plūrālia tantum nouns, e. g. ūna castra (one [military] camp), ūnae scālae (one ladder).
|ūnus, ūna, ūnum|
|Genitive||ūnīus / ūnius||ūnōrum||ūnārum||ūnōrum|
|duo, duae, duo|
|ambō, ambae, ambō|
|Accusative||trēs / trīs|
The numeral centum ('one hundred') is indeclinable, but all the other hundred numerals are declinable.
|ducentī, ducentae, ducenta|
The word mīlle 'thousand' is a singular indeclinable adjective. However, its plural, mīlia, is a plural third-declension i-stem neuter noun. To write the phrase "four thousand horses" in Latin, the genitive is used: quattuor mīlia equōrum, literally, "four thousands of horses".
The rest of the numbers are indeclinable whether used as adjectives or as nouns.
For further information on the different sets of Latin numerals, see Latin numerals (linguistics).
Adverbs and their comparatives and superlatives
Adverbs are not declined. However, adverbs must be formed if one wants to make an adjective into an adverb.
Adverbs from first- and second-declension adjectives
First and second declension adjectives' adverbs are formed by adding -ē onto their stems.
|clārus, clāra, clārum ('clear, famous')||clārē ('clearly, famously')|
|validus, valida, validum ('strong, robust')||validē ('strongly, robustly')|
|īnfīrmus, īnfīrma, īnfīrmum ('weak')||īnfīrmē ('weakly')|
|solidus, solida, solidum ('complete, firm')||solidē ('completely, firmly')|
|integer, integra, integrum ('whole, fresh')||integrē ('wholly, freshly')|
|līber, lībera, līberum ('free')||līberē ('freely')|
Adverbs from third declension adjectives
Typically, third declension adjectives' adverbs are formed by adding -iter to the stem. However, most third declension adjectives with one ending simply add -er to the stem.
|prūdēns, prūdēns (prūdentis) ('prudent')||prūdenter ('prudently')|
|audāx, audāx (audācis) ('bold')||audācter ('boldly')|
|virīlis, virīle ('courageous, spirited')||virīliter ('courageously, spiritedly')|
|salūbris, salūbre ('wholesome')||salūbriter ('wholesomely')|
Comparative and superlative of adverbs
Adverbs' comparative forms are identical to the nominative neuter singular of the corresponding comparative adjective. Adverbs' superlative forms are simply formed by attaching the regular ending -ē to the corresponding superlative adjective. As with their corresponding adjectival forms, first and second declensions adjectives ending in -eus or -ius use magis and maximē as opposed to distinct endings.
|clārē ('clearly, famously')||clārius||clārissimē|
|solidē ('completely, firmly')||solidius||solidissimē|
|idōneē ('suitably, properly')||magis idōneē||maximē idōneē|
Irregular adverbs and their comparative and superlative forms
As with adjectives, there are irregular adverbs with peculiar comparative and superlative forms.
|bene ('well')||melius ('better')||optimē ('best')|
|male ('badly, ill')||peius ('worse')||pessimē ('worst')|
|magnopere ('greatly')||magis ('more')||maximē ('most')|
|multum ('much, a lot')||plūs ('more')||plūrimum ('most')|
|parvum ('little')||minus ('less')||minimē ('least')|
|nēquiter ('worthlessly')||nēquius ('more worthlessly')||nēquissimē ('most worthlessly')|
|saepe ('often')||saepius ('more often')||saepissimē ('most often')|
|mātūrē ('seasonably, betimes')||mātūrius ('more seasonably')||māturrimē ('most seasonably')|
|prope ('near')||propius ('nearer')||proximē ('nearest, next')|
|nūper ('recently')||—||nūperrimē ('most recently, previously')|
|potis ('possible')||potius ('rather')||potissimē ('especially')|
|—||prius ('before, previously')||prīmō ('first')|
Peculiarities within declension
Irregularity in number
Some nouns are only used in the singular (singulare tantum) such as:
- materials, such as aurum 'gold'
Some nouns are only used in the plural (plurale tantum), or when plural have a singular meaning such as:
- many festivals, such as Saturnālia 'Saturnalia'
- castra 'camp' and arma 'arms'; litterae 'a letter' (cf. littera 'letter of the alphabet')
- a few geographical names are plural such as Thēbae 'Thebes' (both the Greek and the Egyptian cities)
Indeclinable nouns are nouns which only have one form in all cases (of the singular).
- fās ('divine law')
- īnstar ('likeness')
- māne ('morning')
- nefās ('sin, abomination')
- secus ('(male or female) sex')
Heterogeneous nouns are nouns which vary in respect to gender.
- A few nouns in the second declension occur in both the neuter and masculine. However, their meanings remain the same.
- Some nouns are one gender in the singular, but become another gender in the plural. They may also change in meaning.
|balneum n. ('bath')||balneae f. or balnea n. ('bathhouse')|
|epulum n. ('feast, banquet')||epulae f. ('feast, banquet')|
|frēnum n. ('bridle, curb')||frēnī m. bridle, curb|
|iocus m. ('joke, jest')||ioca n. or ioci m. ('jokes, fun')|
|locus m. ('place, location')||loca n. ('region'); locī m. ('places in books, arguments')|
|rāstrum n. ('hoe, rake')||rāstrī m. ('hoes, rakes')|
Plurals with alternative meanings
|aedēs, aedis f. ('building, temple')||aedēs, aedium ('rooms, house')|
|auxilium, auxiliī n. ('help, aid')||auxilia, auxiliōrum ('auxiliary troops')|
|carcer, carceris m. ('prison, cell')||carcerēs, carcerum ('starting traps')|
|castrum, castrī n. ('fort, castle, fortress')||castra, castrōrum ('military camp, encampment')|
|cōpia, copiae f. ('plenty, much, abundance')||cōpiae, copiārum ('troops')|
|fortūna, fortūnae f. ('luck, chance')||fortūnae, fortūnārum ('wealth, fortune')|
|grātia, grātiae f. ('charm, favor')||grātiae, grātiārum ('thanks')|
|impedīmentum, impedīmentī m. ('impediment, hindrance')||impedīmenta, impedīmentōrum ('baggage, baggage train')|
|littera, litterae f. ('letter [alphabet]')||litterae, litterārum ('letter [message], epistle, scholarship, literature')|
|mōs, mōris m. ('habit, inclination')||mōrēs, mōrum m. ('morals, character')|
|opera, operae f. ('trouble, pains')||operae, operārum m. ('workmen')|
|*ops, opis f.[i] ('help')||opēs, opium ('resources, wealth')|
|pars, partis f. ('part, piece')||partēs, partium ('office, function')|
- Nominative and dative are not attested except as the name of the goddess Ops.
- Declension of Greek nouns in Latin
- Latin conjugation
- Latin mnemonics
- William Whitaker's Words
- Greek declension
- Aelius Donatus, Ars Major, 2.8.
- Mongan, James Roscoe (1861). The School and University Eton Latin Grammar, Explanatory and Critical. London 1861.
- Paul Crouzet (1902), Grammaire Latine, simple et complète, p. 7.
- Rosa (1962), a song by the Belgian singer Jacques Brel, with the declension of rosa, rosa, rosam following the British order of cases.
- Allen and Greenough. §43 c.
- Allen and Greenough. §49 a.
- Gildersleeve & Lodge §15, Allen & Greenough §12, §49c
- Perseus database.
- Gildersleeve & Lodge, Latin Grammar 3rd ed., p. 17.
- Chambers's Etymological Dictionary Enlarged Edition 1931
- June 1999 issue of ASM News by the American Society for Microbiology
- Nuntii Latini: Finnish Broadcasting Company (Radiophonia Finnica Generalis). Archiv I. 19.5.2000 – 6.12.2002: "NOVUM VIRUS COMPUTATORIUM
Novum viri computatorii genus nomine Code Red in praesenti in Interreti grassatur, ut nuntiavit institutum SANS, cuius est securitati retis informatici providere. Code Red II, quod per cursum electronicum diffunditur, priore viro acerbius est et, postquam in servitoria penetravit, in systema lacunam facit. Ita fieri potest, ut alia vira eaque etiam periculosiora in machinas computatorias irrepant. Iam vermis Code Red I molestissimus fuit, cum biduo in trecenta milia computatrorum in omni orbe terrarum invasit."
- Pons: virus
- William T. Stearn: Botanical Latin. History, Grammar, Syntax, Terminology and Vocabulary. David & Charles, third edition, 1983. Quote: "Virus: virus (s.n. II), gen. sing. viri, nom. pl. vira, gen. pl. vīrorum (to be distinguished from virorum, of men)."
- Allen and Greenough. §80.
- Gildersleeve & Lodge (1895), p. 18.
- Gildersleeve & Lodge (1895), p. 27.
- Cicero, Epistulae ad Atticum 6.1.20 etc.
- Cicero, Pro Rabirio Postumo 4
- Cicero, Pro Milone 29
- Cornelius Nepos, Hannibal 12.2
- Gildersleeve & Lodge (1903), Gildersleeve's Latin Grammar, p. 39.
- Plinius Caecilius Secundus, Gaius (1518). "C. Plinii Secvndi Novocomensis Epistolarum libri X.: Eiusdem Panegyricus Traiano Principi dictus. Eiusdem de Viris illustrib. In re militari, [et] in administranda rep. Suetonij Tranquilli de Claris Grammaticis, [et] Rhetoribus. Iulij Obsequentis Prodigiorum liber. Indices duo, quorum altero nomina referuntur eorum, ad quos Plinius scribit, altero quicquid memoratu dignum toto opere continetur. Latina interpretatio dictionum, [et] sententiarum, quibus Plinius utitur".
- Patin, Guy; Reveillé-Parise, Joseph-Henri (1846). Lettres de Gui Patin. Chez J.-B. Baillière. p. 155.
- Latin declensor (in Spanish)
- New Latin Grammar, an eBook, originally written by Charles Edwin Bennett, at the Project Gutenberg
- Interactive Latin Word Endings
- A Student's Latin Grammar, by Cambridge Latin Course's Robin m. Griffin, Third Edition
- Gildersleeve, B. L.; Gonzalez Lodge (1895). Gildersleeve's Latin Grammar (3rd ed.). Macmillan. ISBN 0-333-09215-5.
- Greenough, J. B.; G. L. Kittredge; A. A. Howard; Benj. L. D'Ooge (1903). Allen and Greenough's New Latin Grammar for Schools and Colleges. Ginn and Company.