Regularly inflected Latin nouns have two
principal parts: 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). This ending can be removed from the genitive singular form to find the noun's oblique stem, which is shared between all inflected forms aside from the nominative singular. (The nominative singular sometimes, but not always has a distinct stem.) Latin declension is commonly taught in terms of attaching different sets of vowel-initial endings to the oblique stem. For example, the first-declension noun 'cow' has the genitive singular , with the oblique stem . Its ablative singular can be formed by combining with the ending , forming . The second-declension noun 'bull' has the genitive singular , with the oblique stem . Its ablative singular can be formed by combining with the ending , forming . There are five declensions (in other words, five such sets of endings) 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. ('road') and ('water'). There is a small class of masculine exceptions generally referring to occupations, e.g. ('poet'), ('farmer'), ('auriga, charioteer'), ('pirate') and ('sailor'). Neuter nouns do not occur in the first declension, with the sole exception of or ('Easter'), which is sometimes neuter and sometimes feminine. 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. The locative endings for the first declension are
-ae (singular) and
-īs (plural), similar to the genitive singular and ablative plural, as in '''' 'in war' and '''' 'at Athens'.
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 ('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 ('horse') and ('boy') and neuter nouns like ('fort'). There are several small groups of feminine exceptions, including names of
gemstones, plants, trees, and some towns and cities: these take the same endings as masculine nouns. 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. Regardless of gender, every second-declension noun has the ending
-ī attached as a suffix to the stem of the noun in the genitive singular form. The predominant letter in the ending forms of this declension is
o. The locative endings for the second declension are
-ī (singular) and
-īs (plural); "at Corinth", "at Milan", and "at Philippi".
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 ) 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 . There is no contraction of
-iī(s) in plural forms and in the locative. In the older language, nouns ending with
-vus,
-quus and
-vum take
o rather than
u in the nominative and accusative singular. For example, ('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 in the genitive and other cases. For example, ('father-in-law') keeps its
e. However, the noun ('(school)master') drops its
e in the genitive singular. For declension tables of second-declension nouns, see the
corresponding Wiktionary appendix. The vocative
puere is found but only in
Plautus. The genitive plural
virum is found in poetry.
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, can appear as
theātrum.
Irregular forms Deus The inflection of ('god') is irregular. The vocative singular of
deus is not attested in Classical Latin. In
Ecclesiastical Latin the vocative of
Deus ('God') is
Deus. In poetry,
-um may substitute
-ōrum as the genitive plural ending.
Virus Three words, although second declension neuter, end in
-us. These are "common people, crowd", "slime, poison", and (borrowed from Greek) "sea". The word means "1. slimy liquid, slime; 2. poison, venom", denoting the venom of a snake. This Latin word is probably related to the
Greek (
ios) meaning "venom" or "rust" and the
Sanskrit word '''' meaning "toxic, poison". Since in antiquity denoted something uncountable, it was a
mass noun. Mass nouns pluralize only under special circumstances, hence the non-existence of plural forms in the texts. In Classical Latin, the noun is either indeclinable (all case forms are ) or declined according to the second declension, but with the ending
-us instead of
-um in the nominative, vocative and accusative. In
Neo-Latin, a plural form is necessary in order to express the modern concept of 'viruses', which leads to the following declension:
Third declension 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, feminine, and neuter nouns.
Consonant stems The stem of a consonant-stem noun may be found from the genitive case by removing the ending
-is. For example, the stem of 'peace' is
pāc-, the stem of 'river' is
flūmin-, and the stem of 'flower' is
flōr-. Masculine, feminine and neuter nouns often have their own special nominative singular endings. For instance, many masculine nouns end in
-or (, 'love'). Many feminine nouns end in
-īx (, 'phoenix'), and many neuter nouns end in
-us with an
r stem in the oblique cases ( 'burden'; 'time'). The locative endings for the third declension are
-ī or
-e (singular) and
-ibus (plural), as in 'in the country' and 'at Tralles'.
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 and the nominative. For example: ('ship'); ('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: ('part'). ;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'); ('spoon'); ('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 plural ending
-īs is found in early Latin up to
Virgil, but from the early empire onwards it was replaced by
-ēs. The accusative singular ending
-im is found only in a few words: always in 'cough', 'thirst', 'River Tiber'; usually in 'axe', 'tower', 'poop', 'fever'; occasionally in 'ship'. Most nouns, however, have accusative singular
-em. The ending
-im is not found in any adjectives, even those that have a separate feminine such as 'swift' or 'keen', or in any masculine common nouns. The ablative singular
-ī is found in nouns which have
-im, and also, optionally, in some other nouns, e.g. or 'in the fire'. There are two mixed-declension neuter nouns: ('heart') and ('bone'). The mixed declension is also used in the plural-only adjective ('most'). 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 ('dog') or ('youth'), which have genitive plural 'of dogs' and 'of young men'. Likewise, ('father'), ('mother'), ('brother'), and ('parent') violate the double-consonant rule. This fluidity even in Roman times resulted in much more uncertainty in Medieval Latin. Some nouns in
-tāt-, such as 'city, community' can have either consonant-stem or
i-stem genitive plural: or 'of the cities'.
Fifth declension (e stems) The fifth declension is a small group of nouns consisting of mostly feminine nouns like ('affair, matter, thing') and
diēs, diēī ('day'; but in names of days). Nouns ending in
-iēs have long
ēī in the dative and genitive, while nouns ending in a consonant +
-ēs usually have short
eī in these cases. Other forms of the genitive singular are also found, such as (
Aeneid 1.636), (
Georgic 1.208), (Ennius). The locative ending of the fifth declension was
-ē (singular only), identical to the ablative singular, as in ('today'). == Pronouns ==