Third Declension Neuters

by Steve
(San Francisco)

Dear Latin Teacher,

What is the rule governing third declension neuters in the plural; some have an -a in the nominative and accusative case while some have an -ia?

Thank you, Steve


Dear Steve,

For neuter nouns, this comes down to the fact that certain neuter nouns of the third declension are i-stem.

Not much help in predicting which nouns will have the extra -i- in the nominative and accusative plural, I know. But that's the truth of it. Generally, neuter nouns with nominative singular ending in -e, -al, -ar will be i-stem.

Most commonly in school books, the word mare, maris is i-stem. So we have maria for the plural nominative and accusative and mari for the singular ablative. Also marium for plural genitive. See also animal (animalia) and exemplar (exemplaria).

Third declension adjectives, however, tend to be i-stem. For nearly all adjectives of the third declension neuter you will find the -ia for the plural nominative and accusative, -ium for the plural genitive, and -i for the singular ablative. (Although the -e is also common in the ablative singular.)

One common exception found in most school books in the adjective vetus, veteris (old). This adjective is NOT i-stem. See the plural forms vetera, veterum.

Hope this helps, and thanks for asking a Latin teacher!

Sincerely,

John

See more Latin Roots!

Study more Vocabulary!