Master Latin adjective agreement — matching adjectives to nouns in gender, number, and case. Learn first/second declension adjectives, third declension adjectives, comparatives, and superlatives.
Estimated Time: 40–50 minutes
In Latin, adjectives must agree with their noun in three ways: gender, number, and case. However, they do NOT have to use the same declension — a third declension adjective can modify a first declension noun.
Vir fortis (the brave man): vir is 2nd declension masculine, fortis is 3rd declension — different endings, but both are nominative singular masculine. They agree even though they don't rhyme.
These use first declension endings for feminine and second declension for masculine/neuter. Dictionary entry shows three forms: m., f., n.
Model: bonus, bona, bonum — good
| Case | M. Sg. | F. Sg. | N. Sg. | M. Pl. | F. Pl. | N. Pl. |
|---|---|---|---|---|---|---|
| Nom. | bonus | bona | bonum | bonī | bonae | bona |
| Gen. | bonī | bonae | bonī | bonōrum | bonārum | bonōrum |
| Dat. | bonō | bonae | bonō | bonīs | bonīs | bonīs |
| Acc. | bonum | bonam | bonum | bonōs | bonās | bona |
| Abl. | bonō | bonā | bonō | bonīs | bonīs | bonīs |
Common 1st/2nd declension adjectives: magnus, -a, -um (great), malus, -a, -um (bad), parvus, -a, -um (small), multus, -a, -um (much/many), pulcher, pulchra, pulchrum (beautiful), liber, lībera, līberum (free).
These come in three varieties based on their nominative forms:
| Type | Nominative Forms | Example |
|---|---|---|
| Three-termination | m. / f. / n. | ācer, ācris, ācre (sharp, keen) |
| Two-termination | m.&f. / n. | fortis, forte (brave, strong) |
| One-termination | all genders same | fēlīx, fēlīcis (happy, lucky) |
Third declension adjectives are i-stems: ablative singular -ī, genitive plural -ium, neuter plural nom/acc -ia.
Common: fortis, -e (brave), omnis, -e (every/all), gravis, -e (heavy/serious), brevis, -e (short), fēlīx, -īcis (happy), ingēns, -entis (huge).
| Degree | Formation | Example (fortis) |
|---|---|---|
| Positive | base form | fortis — brave |
| Comparative | stem + -ior (m/f), -ius (n) | fortior — braver / rather brave |
| Superlative | stem + -issimus, -a, -um | fortissimus — bravest / very brave |
bonus → melior → optimus (good, better, best)
malus → peior → pessimus (bad, worse, worst)
magnus → maior → maximus (great, greater, greatest)
parvus → minor → minimus (small, smaller, smallest)
multus → plūs → plūrimus (much, more, most)
These irregulars survive in English: major, minor, optimal, pessimist, plus!
1. In "puella bona," why does the adjective end in -a?
2. What is the comparative of "bonus"?
✦ Adjectives agree with nouns in gender, number, and case — but NOT necessarily in declension.
✦ 1st/2nd declension adjectives: bonus, -a, -um. 3rd declension: fortis, -e or fēlīx, -īcis.
✦ Comparative: stem + -ior/-ius. Superlative: stem + -issimus, -a, -um.
✦ Key irregulars: bonus/melior/optimus, malus/peior/pessimus, magnus/maior/maximus.