Latin declension

Latin is an inflected language, and as such has nouns, pronouns, and adjectives that must be declined (i.e. their endings alter to show grammatical case). A set of declined forms of the same word pattern is called a declension. There are five declensions, which are numbered and grouped by ending and grammatical gender. For simple declension paradigms, visit the Wiktionary appendices: First declension, Second declension, Third declension, Fourth declension, Fifth declension. Each noun follows one of these five declensions.

Grammatical cases

A complete Latin noun declension consists of up to seven grammatical cases: nominative, vocative, accusative, genitive, dative, ablative and locative.

They are often abbreviated to the first three letters.

The sequence NOM-VOC-ACC-GEN-DAT-ABL has been the usual order taught in Britain and many Commonwealth countries since the publication of Hall Kennedy's Latin Primer (1866). It reflects the tendencies of different cases to share similar endings (see Syncretic trends below). For a discussion of other sequences taught elsewhere, see here. However, some schools teach it in the order NOM-GEN-DAT-ACC-ABL-VOC, as first given.

Meanings and functions of the various cases

• The nominative case marks the subject of a statement and denotes the person or object that performs the action of the verb in the sentence. For example "Mary is going to the store" or "Mary is my sister". It is also used for the predicate: "Mary is my sister". The nominative singular (for adjectives, masculine nominative singular) is used as the reference form of the word.
• The vocative case is used to address someone or something in direct speech. In English, this function is expressed by intonation or punctuation: "Mary, are you going to the store?" or "Mary!" ("Mary" is vocative).
• The accusative case marks the direct object of a verb. It also has various other functions, e.g. it is governed by some prepositions.
• The genitive case expresses possession, measurement, or source. Many of its uses correspond in English to uses of the preposition "of", and in some situations to the English "possessive" case.
• The dative case marks the recipient of an action, the indirect object of a verb. In English, the prepositions to and for frequently correspond to this case, though there are also many uses of these prepositions which do not correspond to the dative case.
• The ablative case expresses separation, indirection, or the means by which an action is performed. In English, the prepositions by, with, from, in and on are most commonly used to indicate these meanings.
• The locative case expresses the place where an action is performed. In early Latin the locative case had extensive use, but in Classical Latin the locative case was very rarely used, applying only to the names of cities and small islands and to a few other isolated words. For this purpose, the Romans considered all Mediterranean islands to be "small" except for Sicily, Sardinia, Corsica, Crete, and Cyprus. Much of the case's function had been absorbed into the ablative. In the singular first and second declension, the locative is identical to the genitive singular form, and in the singular third declension, the locative is identical to the ablative singular form. For plural nouns of all declensions, the locative is also identical to the ablative form. The few fourth and fifth declension place names would also use the ablative form for the locative case. However, a few nouns use the locative instead of a preposition: Domus → Domī (at home), Rūs → Rūrī (in the country), Humus → Humī (on the ground), Militia → Militiae (in military service, in the field), Focus → Focī (at the hearth; at the center of the community). In archaic times, the locative singular of third declension nouns was interchangeable between ablative and dative forms, but in the Augustan period, the use of the ablative form became fixed.

The same ending is often used for more than one case

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:

• The vocative form is the same as the nominative in both singular and plural, except for 2nd declension masculine nouns ending in -us and a few nouns of Greek origin. For example, the vocative of Aeneās is Aenea, although Aeneās is 1st declension.
• The dative is always the same as the ablative in the plural, and in the singular in the 2nd declension, the 3rd declension full i-stems (i.e. neuter i-stems, adjectives), and 4th declension neuters.
• The genitive singular is the same as the nominative plural in 1st, 2nd, and 4th declension masculine and feminine nouns.
• The dative singular is the same as the genitive singular in 1st and 5th declension nouns.
• For neuter plural nouns, the nominative, vocative and accusative all always ends in -a (with a few exceptions: demonstrative hic and related istic and illic, relative/interrogative quī and related words; in all of these, the neuter plural takes the same form as feminine nominative singular).
• The accusative singular ends in a short vowel plus -m, except for some neuters.
• In masculines and feminines, the accusative plural ends in a long vowel plus -s; so does the nominative plural in the 3rd, 4th and 5th declensions.
• The locative is identical to the ablative in the 4th and 5th declensions.
• The dative, ablative and locative are identical in the plural.

History of cases

Old Latin had essentially two patterns of endings. One pattern was shared by the first and second declensions, with a clear similarity to the first and second declensions of Ancient Greek. The other pattern was used by the third declension and was very different from Greek, even for direct cognates. When new words were absorbed into Latin, they were generally placed in the third declension.

Nouns

There are five declensions for Latin nouns:

First declension (a)

Nouns of this declension usually end in –a in the nominative singular and are mostly feminine, e.g. 'road' (via, viae fem.) and 'water' (aqua, aquae fem.). There is a small class of masculine exceptions generally referring to occupations, e.g. 'farmer' (agricola, agricolae masc.) and 'sailor' (nauta, nautae masc.).

The predominant letter in the ending forms of this declension is a. The nominative singular form consists of the stem and the ending -a, and the genitive singular form is the stem plus -ae.

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 are sometimes treated as if they were native Latin nouns, e.g. nominative athlēta instead of the original athlētēs. Interestingly, 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)

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.

Masculine:

Neuter:

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 [werˈɡiliː], with stress on the penult, even though it is short.^[2]

There is no contraction of -iī(s) in plural forms.

Second declension R nouns

Some masculine nouns of the second declension end in an –er or an –ir in the nominative singular. For such nouns, the genitive singular must be learned to see if the E is dropped. For example, socer, –erī keeps its E. However, the noun magister, –trī ("teacher") drops its E in the genitive singular. Nouns with –ir in the nominative singular never drop the I.

The declension of second declension R nouns is identical to that of the regular second declension, with the exception of the vocative singular, which is identical to the nominative rather than ending in an -e.

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.

Peculiarities

In the older language, nouns ending with –vus, –quus and –vum take o rather than u in the nominative and accusative singular.

The plural of deus (god, deity) is irregular.

Nom.	dī/diī/deī
Voc.	dī
Acc.	deōs
Gen.	deōrum/deum
Dat.	dīs/diīs/deīs
Abl.	dīs/diīs/deīs

The vocative singular of Deus is not attested in Classical Latin. In Ecclesiastical Latin the vocative is Deus.

In poetry, -um may be substituted for -ōrum as the genitive plural ending.

Third declension (i)

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. Examples are flumen, fluminis neut. ("river"), flos, floris masc. ("flower"), and pax, pacis fem. ("peace"). Each noun has the ending -is as a suffix attached to the root of the noun in the genitive singular form. Masculine, feminine and neuter nouns each have their own special nominative singular endings. For instance, many masculine nouns end in an –or (amor). Many feminine nouns end in an –īx (phoenīx), and many neuter nouns end in an –us (onus).

¹ The nominative singular is formed in one of four ways: with -s, with no ending, or by one of these two with a different stem from the oblique cases. The same is true of other forms that are the same as the nominative singular: the vocative singular and the neuter accusative singular.

² The nominative and accusative of neuter nouns are always identical. It should not be assumed that –en is always the appropriate ending, as it might appear above.

Third declension i-stem 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 the parisyllabic rule or special neuter endings. Mixed I-stems are indicated by the double consonant rule.

• Masculine & 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: amnis, –is. The nominative ends in -is.
  • 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
• Neuter
  • Special Neuter Ending: Neuter third declension i-stems have no rule. However, all of them end in –al, –ar or –e. For example: animal, –ālis. This can be remembered with the help of the mnemonic involving a pirate named Al: "Al, ar' e' going pirating today?"

Pure I-stems may exhibit peculiar endings in both singular and plural. Mixed I-stems employ normal (consonant) 3rd declension endings in the singular but I-Stem endings in the plural. Note the alternative I-stem endings indicated in parentheses.

¹ The nominative singular is formed in one of four ways: with -s, with no ending, or by one of these two with a different stem from the oblique cases. The same is true of other forms that are the same as the nominative singular: the vocative singular and the neuter accusative singular.

The rules for determining I-stems from non-I-stems and "mixed" I-stems should be thought of more as "guidelines" than "rules": even among the Romans themselves, the categorization of a 3rd declension word as an I-stem or non-I-stem was quite fluid. The result is that many words that should be I-stems according to the parisyllabic and consonant stem rules actually are not, such as canis or iuvenis. By the parisyllabic rule, "canis" should be a masculine I-stem and thus differ from the non-I-stems by having an extra -i- in the plural genitive form: "canium". In reality, the plural genitive of "canis" is "canum", the form of a non-I-stem. This fluidity even in Roman times results in much more uncertainty in Medieval Latin, as scholars were trying to imitate what was fluid to begin with.

Peculiarities

In the third declension, there are four irregular nouns.

Fourth declension (u)

The fourth declension is a group of nouns consisting of mostly masculine words such as fluctus, fluctūs (masc.) ("a wave")' and portus, portūs (masc.)("a port") with a few feminine exceptions, including manus, manūs (fem.) ("hand"). The fourth declension also includes several neuter nouns including genu, genūs (neut.) ("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.

In the dative and ablative plural, –ibus is sometimes replaced with –ubus. This is so for only a few nouns, such as artus, "the limbs".

The declension of domus is irregular:

Fifth declension (e)

The fifth declension is a small group of nouns consisting of mostly feminine words like 'affair, matter, thing' (rēs, reī fem.) and 'day' (diēs, diēī usually masculine, except on notable days when it is feminine). Each noun has either the ending -ēī or –eī as a suffix attached to the root of the noun in the genitive singular form

Note that 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.

Pronouns

Relative and demonstrative 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 identify the "pronominal" declension, and a few adjectives follow this pattern. The vocative, where not shown, is the same as the nominative.

Personal pronouns

The first and second persons are irregular. They may be only masculine or feminine.

¹These pronouns are declined in the 1st and 2nd declensions to agree in number and case with the thing possessed.

Usually, to show the ablative of accompaniment, cum would be added to the ablative form. However, with personal pronouns and the interrogative (not with 3rd person), cum is added on to the end of the ablative form. For example: mēcum, nōbīscum, tēcum, vōbīscum and quōcum (sometimes quīcum).

The third person reflexive pronouns always refer back to the subject whether it be singular or plural.

¹This pronoun is declined in the 1st and 2nd declensions to agree in number and case with the thing possessed.

Interrogative pronouns

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.

Demonstrative pronouns and adjectives

Intensive pronouns

Relative pronouns

Adjectives

First and second declension adjectives

First and second declension 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, adjectives are given like altus, alta, altum.

First and second declension –r adjectives

Some first and second declension adjectives' masculine form end in an –er. As with second declension nouns –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.

First and second –īus genitive adjectives

Nine first and second declension adjectives are irregular in the genitive and the dative in all genders. They can be remembered by using the mnemonic acronym UNUS NAUTA. They are:

ūllus, –a, –um; any
nūllus, –a, –um; no, none (of any)
uter, –tra, –trum; which (of two)
sōlus, –a, –um; sole, alone
neuter, –tra, –trum; neither (of two)
alius, –a, –ud; (gen. sing. alīus; another)
ūnus, –a, –um; one
tōtus, –a, –um; whole
alter, –era, –erum; the other (of two)

Third declension adjectives

Third declension adjectives are normally declined like third declension i-stem nouns, except for the fact they always have a –ī rather than an -e in the ablative singular (unlike i-stem nouns, in which only neuters have –ī). Some adjectives, however, like the one-ending vetus, veteris (old, aged), have an -e in the ablative singular (all genders), a -um in the genitive plural (all genders), and an -a in the nominative and accusative plural (neuter only).

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 inflection.

¹—may end in –īs
²—may end in –e

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. Because the sexed form ends in an –is, we find the adjective genitive singular.

¹—may end in –īs

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 an –er. The feminine ends in an –ris, and the neuter ends in an –re. With that information, we come upon the genitive singular needed for inflection, the feminine form.

¹—may end in –īs

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 an –ior for the masculine and feminine, and an –ius for the neuter to the base. The genitive for both are formed by adding an –iōris. Therefore, they are declined like the third declension. However, they are not declined as i-stems are. Superlatives formed by adding an –issimus, –a, –um to the base. Now, we find that superlatives are declined like first and second declension adjectives.

Comparatives and superlatives of –er adjectives

Adjectives (in the third and first and second declensions) that have masculine nominative singular forms ending in –er have different forms. If the feminine and neuter forms drop the E, use that for the comparative form. The superlative is formed by adding a –rimus onto the masculine form.

Comparatives and superlatives of –lis adjectives

Some third declension adjectives with two endings in –lis in the sexed nominative singular have irregular superlative forms. The following are the only adjectives that have this unique form.

Irregular comparatives and superlatives

As in most languages, Latin has adjectives that have irregular comparatives and superlatives.

• 1: noun used with genitive to express more of something
• 2: often replaced by the regular form 'maturissimus, –a, –um'
• 3: indeclinable

Declension of īdem

The adjective īdem, eadem, idem means 'same.' It is a variant of the third person pronouns that were declined earlier. Generally, they are formed by adding –dem to a declined third person pronouns. However, some forms have been changed to ease pronunciation.

Declension of numerals

See also: Roman numerals for symbology.

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 such as distributive numerals and adverbial numerals

Cardinal numerals

All numerals, except ūnum (one), duo (two), tria (three), centum (one hundred), and mīlia (thousand, sing. mīlle) are indeclinable adjectives. Ūnus, ūna, ūnum is declined like a first and second declension adjective with an –īus in the genitive, and –ī in the dative. Duo is declined irregularly, and tria is declined like a third declension adjective.

It should be noted that ambō, "both", is declined as duo is, though its o is long.

The word mīlle, is singular, an adjective and indeclinable. However, its plural, mīlia, is a plural 3rd declension I-stem neuter noun.

• Note that to write the phrase "four thousand horses" in Latin, the genitive is used: "quattuor milia equōrum", literally, "four thousands of horses".

As stated before, the rest of the numbers are indeclinable adjectives. They are also indeclinable as substantives.

Ordinal numerals

Ordinal numerals all decline like normal 1st and 2nd declension adjectives.

• Primus = first
• Secundus = second
• Tertius = third
• Vicensimus = twentieth

Note: "secundus" only means "second" in the sense of "following". The adjective alter, -ra, -rum meaning "the other (of two)" was more frequently used in many instances that English would use "second".

Ordinal numbers, not cardinal numbers, are commonly used to represent dates, because they are in the format of "in the tenth year of Caesar", etc. which also carried over into the Anno Domini system and Christian dating, i.e. "anno post Christum natum centesimo"(also "centensimo") = AD 100.

Distributive numerals

A rare numeral construction denoting an equal number distributed among several objects, e.g. "How many each?" "Two by two." They decline like normal 1st and 2nd declension adjectives, and are logically always plural. Bis, Bina = "twice two". A classical example would be "Uxores habent deni duo deniqui inter se communes" = "groups of ten or twelve men had wives in common" –Gallic Wars, Julius Caesar

Adverbial numerals

Adverbial numerals are (as the name states) indeclinable adverbs, but because all of the other numeral constructions are adjectives, they are listed here with them. Adverbial numerals give how many times a thing happened. Semel = once, Bis = twice, Ter = thrice (three times), Quater = four times, etc.

Adverbs and their comparisons and superlatives

Adverbs are not declined. However, adverbs must be formed if one wants to make an adjective into an adverb.

First and second declension adjectives' adverbs

First and second declension adjectives' adverbs are formed by adding an –ē onto their bases.

Third declension adjectives' adverbs

Typically, third declension adjectives' adverbs are formed by adding an –iter onto their bases. However, most third declension adjectives with one ending simply add an –er to their bases.

Adverbs' comparative and superlative forms

Adverbs' comparative forms are their neuter adjectives' comparative forms. Adverbs' superlative forms are made in the same way in which first and second declension adjectives' adverbs are made.

First and second declension adjectives' adverbs are formed by adding an –ē onto their bases.

Irregular adverbs and their comparative and superlative forms

As so with adjectives, there are irregular adverbs with peculiar comparative and superlative forms.

Peculiarities within declension

Irregularity in number

Some nouns are only used in the singular, such as:

• Materials such as aurum (gold) and aes (copper)
• Abstract nouns such as celeritās (speed) and scientia (knowledge)
• Proper names such as Iulius (Julius) and Clāra (Clara)

Some nouns are only used in the plural (plurale tantum) such as:

• Many festivals, such as Saturnalia
• Castra (camp) and arma (arms)
• A few geographical names are plural such as Thēbae (Thebes).

Indeclinable nouns

Indeclinable nouns are neuter nouns which occur only in the nominative and the accusative singular. There are only six such nouns:

• fās — fate, divine law
• īnstar — likeness
• māne — in the morning (arguably this occurs only in the ablative singular; also arguably it is an adverb rather than a noun) It is notable because it occurs in modern medical prescriptions.
• nefās — sin, abomination
• nihil / nil — nothing, none
• secus - sex, coitus

Heterogeneous nouns

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.

Singular	Plural
balneum n. bath	balneae f. or balnea n. bath-house
epulum n. feast, banquet	epulae f. feasts, banquets
frēnum n. bridle, curb	frēnī m. bridle, curb
iocus m. joke, jest	ioca n. or ioci m. jokes, jests
locus m. place, location	loca n. places, locations; locī region
rāstrum n. hoe, rake	rāstrī m. hoes, rakes

Plurals with alternative meanings

Nouns whose plural meaning is different from the singular meaning are called plūrālia tantum.

Singular	Plural
aedēs, –is f. building, temple	aedēs, –ium rooms, house
auxilium, –ī n. help, aid	auxilia, –ōrum auxiliary troops
carcer, –eris m. prison, cell	carcerēs, –um starting-place of a chariot race
castrum, –ī n. fort, castle, fortress	castra, –ōrum milit. camp, encampment
cōpia, –ae f. plenty, much, abundance	cōpiae, –ārum troops
fīnis, –is m. end, boundary	fīnēs, –ium territory
fortūna, –ae f. luck, chance	fortūnae –ārum wealth
grātia, –ae f. charm, favor	grātiae, –ārum thanks
impedīmentum, –ī m. impediment, hindrance	impedīmenta, –ōrum baggage
littera, –ae f. letter (as in A, B, C, etc.)	litterae, –ārum epistle, scholarship, literature
mōs, mōris m. habit, inclination	mōrēs, –um m. morals, character
opera, –ae f. trouble, pains	operae, –ārum workmen
opis f.[5] help	opēs, –ium resources, wealth
pars, partis f. part, piece	partēs, –ium office, function

See also

• Latin conjugation
• Latin mnemonics
• Plural form of words ending in -us
• William Whitaker's Words
• Greek declension

Notes

References

• Latin declensor (Spanish)
• New Latin Grammar, an eBook, originally written by Charles Edwin Bennett, at the Project Gutenberg
• Latin grammar - interactive
• 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.