Latin declension

Latin noun declension features seven cases:

• nominative (subject; also used with copulative verbs)
• genitive (possessive - of which)
• dative (indirect object - to or for which)
• accusative (direct object)
• ablative (expresses the means or tools by which one accomplishes something)
• vocative (used for addressing another person in direct speech, usually identical to nominative)
• locative (archaic; used to show location in cities, towns, and small islands, and the nouns rus, domus, and humus; forms for the locative are the same as the genitive in the 1st and 2nd declension singular and the same as the ablative in the 3rd declension singular; towns with plural form (Athens) take their locative from the ablative plural in all declensions.)

Note: Neuter nouns of all declension classes share two properties:

• The forms for nominative and accusative singular are identical.
• The forms for nominative and accusative plural are identical, and they always end in -a.

Since this behavior tends to obscure the situation, neuter paradigm words were generally avoided (though this isn't always possible). Neuter pronouns do not always follow the second of these rules, but they do follow the first.

Noun declensions

There are five declension classes:

1. a declension

Nouns of this class usually end in -a and are usually of feminine grammatical gender. Example (paradigma is terra - land, earth):

The a declension has no special forms for the vocative; nominative is used instead. The genitive singular originally had the ending -as (preserved in the expression pater familias) and the dative and ablative plural had -abus (preserved in cum dis et deabus).

Greek words ending in -es or -as (like the name Aeneas) are also declined according to this scheme. They, however, do have a vocative form (stem + -a, e.g. Aenea).

2. o declension

Nouns of this class end in -us, -r or -um. Nouns ending in -us and -r are usually of masculine gender, those ending in -um of neuter gender.

Example I, words ending in -us (paradigma hortus - garden)

Example II, words ending in -um (paradigma verbum - word)

Example III, words ending in -r (paradigma ager - field)

Note that the e in the nominative singular form is just an insertion to ease pronunciation and is omitted in all other forms. There are however some words, where the e belongs to the stem proper and can't be omitted. These are: gener (son-in-law), socer (father-in-law), puer (boy), vesper (evening) and liberi (children - only occurs in plural forms).

Greek words ending in -eus are declined like regular nouns ending in -us, with the single exception that the vocative singular is formed by appending -u to the "stem" (as in Orpheus - Orpheu)

3. mixed declension

Nouns of this class are divided into two subcategories according to the ending of their stems.

3.1 consonantal stems

This class comprises nouns whose stem ends in a consonant. Some nouns of this class don't have a particular ending for nominative singular. Of these, some use the raw stem instead (as with sol - sun), and some have a special contracted form (like natio - people, tribe). Finally, some consonantal nouns have the nominative singular ending "-s" (like rex - king, which originally was regs). Examples:

3.2: short -i stems

This class consists of nouns whose stem ends in a short -i. According to their nominative form, one can subdivide them into three groups: Some nouns (like nubes - cloud) have nominative forms consisting of the same number of syllables as the other forms, some have shortened nominative forms (like ars - art) and some have non-standard nominative forms ending in -e, -al or -ar (like animal - animal). Because when someone knows the nominatives of consonantal stem and short -i stem words the other noun cases are hard to recognize Latin students memorize them by learning their nominative and genitive. Examples:

A small group of nouns has a declension scheme especially rich in "i"s. They are: febris - fever, puppis - quarterdeck, securis - axe, sitis - thirst, turris - tower, tussis - cough and vis - power. Example:

4. u declension

Nouns of this class end in -us or -u. The former ones usually are of masculine gender, the latter ones are always neuter.

Example I, nouns ending in -us (paradigma lacus - lake)

Originally, dative and ablative plural ended in -ubus.

Example II, neuter nouns ending in -u (paradigma cornu - horn)

5. e declension

Nouns of this class end in -es. Nearly all of them are of feminine grammatical gender, with the notable exception of dies, which is masculine. Example (paradigma dies - day):

This declension class is the last to develop in Latin; the only nouns that have the full declension are dies and fides.

Adjective declensions

Adjectives are divided into two declension classes. The first (called the "first and second declension") combines the a and o declensions of nouns, with the a endings added when the adjective is feminine, and the o forms for masculines. Neuter adjectives of this class follow the pattern for o class neuter nouns.

The other class for adjectives (called the "third declension") is similar to the third class for nouns, with the important difference that nearly all these adjectives form the ablative singular in -i, not in -e. The nominative singular of these adjectives is also often marked for gender in various ways.

A small class of adjectives follows the "pronominal declension", described below.

Pronoun declensions

The personal pronouns are declined as follows:

First person:

Case	Singular	Plural
nominative	ego	nos
genitive	mei	nostrum/nostri
dative	mihi	nobis
accusative	me	nos
ablative	me	nobis

Second person

Case	Singular	Plural
nominative	tu	vos
genitive	tui	vestrum/vestri
dative	tibi	vobis
accusative	te	vos
ablative	te	vobis

There are clear patterns here and relations to the noun declensions. (Accusative plural ends in -s; dative and ablative plural are identical; characteristic -i ending in the dative singular, and so forth.)

Relative and demonstrative pronouns are generally declined like first and second declension adjectives, with the following differences:

• the nominatives are often irregular
• the dative singular ends in -i rather than -ae or -o
• the genitive singular ends in -ius rather than -ae or -i.

These differences identify the "pronominal" declension, and a few adjectives also follow this pattern. For example, ille:

The relative pronoun qui and its variants and compounds form their plural dative and ablative in -ibus.

See also

• Latin conjugation