Subject complement

The subject complement is the word (with any accompanying phrase) or clause that follows a linking verb (copula) and complements, or completes, the subject of the sentence by either (1) renaming it or (2) describing it. The former, a renaming noun (or sometimes a pronoun), is technically called a predicate noun or predicate nominative (or in some cases, a predicate pronoun). The latter, a describing adjective, is called a predicate adjective.

Subject complements are used only with a class of verbs called linking verbs or copulative verbs, of which to be is the most common. Unlike object complements, subject complements are not affected by the action of the verb, and they describe or explain the subject.