Adjectives (First Class)
Now that you covered the First and the Second Declensions, it is time to introduce adjectives.
If you have not covered the Second Declension you are strongly advised to study that first and then come back to read this section on adjectives of the first class.
All Latin adjectives of the first class are fully declinable and use the pattern of declensions of the nouns: the masculine and neutral use the second declension paradigm, whereas the feminine gender uses the First Declension paradigm.
First Class Adjectives
Adjectives qualify a noun. In English, they precede the noun they qualify, for example good girl, famous poet, attentive pupil.
In Latin, they can precede or follow the noun they qualify; bona puella, clarus poeta, puer attentus. However, the case of the adjective is always the same as the case of the noun it qualifies.
For convenience these first class adjectives can be grouped in three categories:
Those whose nominative ends in: -us (m.) -a (f.) and -um (n.)
For example: bonus - bona - bonum, meaning good.
Those whose nominative ends in: -er (m.) -era (f.) and -erum (n.)
For example: liber - libera - liberum, meaning free.
Those whose nominative ends in: -er (m.) -ra (f.) and -rum (n.)
For example: pulcher - pulchra - pulchrum, meaning beautiful.
RULE:
The manusculine gender, hence those ending in -us, -er are declined using the rules of the second declension.
The feminine gender. hence those ending in -a, -era and -ra are declined using the rules of the first declension.
The neutral gender, thus -um, -erum and -rum are declined using the rules of the second declension.