First & Second Declension Nouns

Latin nouns sort into five “declensions” — families that share the same set of case endings. The first two declensions cover the majority of common vocabulary.

First declension (mostly feminine): puella, puellae — girl

Second declension (mostly masculine): amīcus, amīcī — friend

Second declension neuter: bellum, bellī — war

Neuter nouns follow the same pattern as masculine second-declension nouns, except the nominative and accusative are always identical, and the plural ends in -a: bellum (sg.) / bella (pl.) for both nominative and accusative.

How to recognize a declension from a dictionary entry

Dictionaries list the nominative and genitive singular together, e.g. puella, puellae or amicus, amici. The genitive ending is the giveaway: -ae signals first declension, -i signals second.