Latin Nouns: Third Declension

What’s with the Hyphens?

Referring to the top two tables — since third declension nouns have a variety of different endings (-a, -e, -i, -o, -c, -l, -n, -r, -s, -t, -x, and -y in some cases), the paradigm charts above mark the nominative case with a hyphen. If the hyphen appears in other parts of the paradigm, it indicates that the nominative form should be used.

Cheat Sheet for Determining Gender

You can usually tell the gender of the noun by the following endings:

• Masculine - Endings: -ō, -or, -ōs, -er, -es
• Feminine - Endings: -ās, -ēs, -is, -ys, -x, -s (preceded by a consonant), -dō, -gō, -iō, -ūs
• Neuter - Endings: -a, -i, -e, -y, -o, -l, -n, -t, -ar, -ur, -us

Neuter nouns

The accusative form of neuter nouns is always the same as its nominative form, no matter what declension.

What’s So Different about the ĭ-stem?

These are the main differences:

• The genitive plural is -ium instead of -um.
• The neuter plural forms of -a become -ia.

Is It an ĭ-stem?

An i-Stem third declension noun has one of the following characteristics:

• The nominative and genitive forms are parisyllabic (meaning they have the same number of syllables). Examples: ignis (gen. ignis), hostis (gen. hostis).
• Or the nominative inflection is monosyllabic (one syllable). The nominative inflection ends in -x or -s, and two consonants precede the suffix in the genitive form. Example: pars, partis (pars is only one syllable, it ends in -s, and the “rt” in partis (genitive form) qualifies it as having two consonants prior to the genitive suffix.
• All nouns in the third declension ending in -e, -al, and -ar are neuter. Examples: mare (sea), portal (portal), templar (templar).

The Rare Accusative

In rare occasions, the accusative form of the masculine and feminine ĭ-Stem nouns is -im. If a word uses this inflection, the ablative for it is also changed to -i. Furthermore, its accusative plural form will most likely end in -is as well.