430. An adjective used as a noun may also be used as the object of a verb, thus:

In these sentences the adjectives rich, poor, weak, good and true, are used as nouns and are the objects of the verbs saw, crushes and seek.

VERBS OF STATE OR CONDITION

We have found that with the incomplete verbs of state or condition, or copulative verbs, the predicate complement may be either a noun, as, The man is a hero; or an adjective, as, The man is class-conscious; or a phrase, as, The man is in earnest.

431. A pronoun; as,

In these sentences the subjects of the verbs are she, that and this, and the pronouns who, he and I are used as predicate complements.

432. Infinitives may also be used as the predicate complement, thus: