Noun rules

Declensions

A group of nouns whose endings change the same way is called a declension. There are five declensions in Latin. Here are some examples of the first two:

example
·a first declension puella
·us or ·er second declension colonus, ager, puer

Noun rules

accusative singular

rule example
·a → ·am puella → puellam
·us → ·um colonus → colonum
ager → agrum
puer → puerum

ablative singular

rule example
·a → ·a puella → puella
·us → ·o colonus → colono
ager → agro
puer → puero

nominative plural

rule example
·a → ·ae puella → puellae
·us → ·i colonus → coloni
ager → agri
puer → pueri

accusative plural

rule example
·a → ·as puella → puellas
·us → ·os colonus → colonos
ager → agros
puer → pueros

ablative plural

rule example
·a → ·is puella → puellis
·us → ·is colonus → colonis
ager → agris
puer → pueris