You have already seen the first and third declensions. Once you learn the second declension, you will know the three primary declensions of Latin – nearly 95% of Latin nouns belong to one of these declensions. Here are all three declensions side by side:
|
|
1st (f.) |
2nd (m.) |
3rd (m./f.) |
|
|
|
Singular |
|
|
Nominative |
a |
us or r |
-- |
|
Genitive |
ae |
ī |
is |
|
Dative |
ae |
ō |
ī |
|
Accusative |
am |
um |
em |
|
Ablative |
ā |
ō |
e |
|
Plural |
|||
|
Nominative |
ae |
ī |
ēs |
|
Genitive |
ārum |
ōrum |
um |
|
Dative |
īs |
īs |
ibus |
|
Accusative |
ās |
ōs |
ēs |
|
Ablative |
īs |
īs |
ibus |
The vocative in the second declension is a bit unusual. You'll remember that in the first and third declensions, the vocative is the same as the nominative. This is sometimes true in the second declension, but not usually.
For second declension nouns that end in r, like puer and vir, the vocative is the same as the nominative. But if a second declension noun ends in us or ius, the vocative is different.
For the second declension:
|
nominative |
→ |
vocative |
|
us |
→ |
e |
|
ius |
→ |
ī |
|
all others |
→ |
same as nominative |
|
Examples: |
||
|
servus |
→ |
serve |
|
filius |
→ |
filī |
|
vir |
→ |
vir |