Genitive forms

Nouns

In the first declension, the genitive endings are:

word genitive singular genitive plural
puella -ae f. puellae puellarum

In the second declension, the genitive endings are:

word genitive singular genitive plural
colonus -i m. coloni colonorum
puer pueri m. pueri puerorum
magister magistri m. magistri magistrorum
templum templi n. templi templorum

In the third declension, the genitive endings are:

word genitive singular genitive plural
rex regis m. regis regum
litus litoris n. litoris litorum

These endings are added to the base of the word. You can find the base of a third declension word by removing ·is from its genitive singular.

Some third-declension nouns have a genitive plural in ·ium. Here are all the third-declension nouns from the first year course whose genitive plural ends in ·ium:

word genitive plural
civis civis c. civium
collis collis m. collium
hostis hostis c. hostium
mare maris n. marium
moenia moenium n. pl. moenium
mons montis f. montium
mors mortis f. mortium
navis navis f. navium
nox noctis f. noctium
urbs urbis f. urbium

Adjectives

In first and second declension adjectives, the genitive endings are:

word genitive singular non-feminine genitive singular feminine genitive plural non-feminine genitive plural feminine
bonus -a -um boni bonae bonorum bonarum
miser misera miserum miseri miserae miserorum miserarum

In third declension adjectives, the genitive endings are:

word genitive singular genitive plural
fortis forte fortis fortium
ingens ingentis ingentis ingentium

Pronouns

earum
their f.
eius
his, her, its
eorum
their m., n.

Possessive adjectives

The genitive forms of the personal pronouns are not used to indicate possession. These pronouns have possessive adjectives instead.

meus -a -um
my
noster nostra nostrum
our
suus -a -um
his, her, its, their
tuus -a -um
your s.
vester vestra vestrum
your pl.