Adjective Declension
In Latin, adjectives must agree with the nouns they modify in gender, number, and case. For example:
- ‘of a rock’ (genitive) = saxī (the noun is neuter, singular, genitive)
- ‘of a large rock’ = magnī saxī (the adjective must be neuter, singular, genitive)
In the dictionary, the adjectival entry given are the nominative singular masculine, feminine, and neuter (in that order). For example:
magnus, magna, magnum large, big, great
In Latin, the 3-gender form exclusively determines the complete declension table of an adjective. We decline adjectives according to the adjective groups they belong to:
Group 1: The 2-1-2 Adjectives (e.g., meus, -a, -um)
These are the most straightforward. They use 2nd declension for masculine/neuter and 1st declension for feminine (hence 2-1-2):
- Masculine: meus (declines like a 2nd declension noun).
- Feminine: mea (declines like a 1st declension noun).
- Neuter: meum (declines like a 2nd declension neuter).
- The Stem: Drop the ending from the feminine form (mea me-).
Group 2: The 3rd Declension Adjectives
These can have one, two, or three “terminations” (forms) in the nominative, but they all follow 3rd declension rules.
1-termination & 2-terminations
The distinction between them is purely about how they present themselves in the nominative singular. To distinguish
these two, we ask: Is the second word a Neuter Nominative or a Genitive?
- If the second word ends in -e: It is 2-Termination, because the first word is M/F, the second is N. The stem is found by dropping the -is from the first word.
- If the second word ends in -is: It is 1-Termination, since the first word is the Nominative for all genders. The second word is the Genitive. The stem is found by dropping the -is from the second word.
| Type | Entry Format | Example | Logic |
|---|---|---|---|
| 2-Term | -is, -e | fortis, forte | M/F matches, Neuter is unique |
| 1-Term | [Any], -is | audāx, -ācis | All genders match, second word is Genitive |
3-Terminations
Although 3-termination and 2-1-2 both show up as 3-form, we can distinguish between them by looking at nominative singular endings of the 3 genders:
- If the Neuter ends in -um: It is 2-1-2. It will follow the same endings as the 2nd declension neuter nouns (bellum).
- If the Neuter ends in -e: It is 3-termination. It will follow the 3rd declension i-stem rules (mare).
Some 2-1-2 adjectives also end in -er in masculine nominative singular (e.g., liber, libera, liberum). Do not let the -er trick you into thinking it’s 3rd declension. Always look at the 2nd and 3rd words. For example
- liber, libera, liberum 2-1-2 (The -a and -um are the dead giveaways)
- ācer, ācris, ācre 3-Termination (The -is and -e signal the 3rd declension)