Subject Complements  

A subject complement is the information that follows a linking verb to describe, identify, or rename the subject of the clause. Whereas most verbs describe the action a subject performs, linking verbs describe something about the subject, which is completed by the subject complement.

A subject complement can either be a predicate noun, a predicate pronoun, or a predicative adjective.

Nouns that follow linking verbs are known as predicate nouns (or sometimes predicative nouns or predicate nominatives). These serve to rename or re-identify the subject. If the noun is accompanied by any direct modifiers (such as determiners, adjectives, or prepositional phrases), the entire noun phrase acts predicatively.

For example:

Noun clauses are dependent clauses that are able to function grammatically like nouns in a sentence. They most commonly begin with the words that, how, if, and the “wh-” words—what, whatever, where, wherever, when, whenever, why, which, whichever, who, whom, whoever, whomever, whether, and whatever.

Because they behave like nouns, they can perform all the roles that a normal noun would fill in a sentence, including as a subject complement. For example:

We can also use a predicate pronoun after a linking verb to re-identify the subject. This is most common in questions and responses in which the identity of the subject is not known or is being explained. For example:

We also commonly use personal pronouns in the possessive case predicatively, as in:

We can also use subjective* personal pronouns in declarative statements, but this is less common in everyday speech and writing, as it tends to make the sentence sound more formal than is usually necessary. For instance:

When pronouns that are not possessive are used predicatively, the conventional rule is to put them in the subjective case rather than the objective case. Pronouns in the objective case (me, us, him, her, them, whom, and whomever) should only be used as direct objects of verbs or prepositions, not as subject complements.

For example, “it was I who did this” is more correct than “it was me who did this.”

In conversational English, however, this distinction is much less frequently observed, and you will often hear people using phrases such as “it’s me” or “that was her” in response to questions.

But in writing (especially formal or professional writing), always use the subjective case for a personal pronoun if it is functioning as a subject complement after a linking verb.

To learn more about using the subjective and objective cases of pronouns, see the section dealing with Case in the chapter on Personal Pronouns.

A predicative adjective is an adjective used after a linking verb to describe or modify the subject of the clause. For example:

Here, nice describes the subject you, while the adjective phrase very handsome describes the subject he.

Note that adjectives appearing immediately before the noun they are describing are known as attributive adjectives. For example:

Old is an attributive adjective that describes the subject, man. Nice also describes man, but it is a predicative adjective because it follows the linking verb seems.

Prepositional phrases can either functions as adjectives (modifying nouns or pronouns) or adverbs (modifying verbs, adjectives, and adverbs). When a prepositional phrase follows a linking verb (especially the verb be), it is functioning in the same way as a predicative adjective, describing the subject (which must be a noun or pronoun). For example:

To learn more about how Predicative Adjectives work, go to their section in the chapter on Adjectives.