22.1 Definitions

A relative clause is a dependent clause that acts like an adjective, but instead of a single word it uses an entire statement to modify a noun. In the sentence Jill won first prize, the adjective first modifies the noun prize. Similarly, in the sentence This is the prize that Jill won, the relative clause that Jill won modifies the noun prize. In English, relative clauses can be marked by the words that, who, whom, which, or whose, but they can also be unmarked: This is the prize Jill won, where the independent statement Jill won is used to modify the noun prize just by the context.

Like adjectives, relative clauses in English normally cannot be used by themselves. When they are used without a noun, English usually requires a word such as one or ones in place of the noun, just as it does for adjectives. Thus, English can say They want a pilot who is experienced or They want one who is experienced but not *They want who is experienced, just as it can say an experienced pilot or an experienced one but not *an experienced. Like adjectives, relative clauses always presume the existence of a noun or noun phrase that they modify, even if the noun or noun phrase is not actually expressed. This noun or noun phrase is called the antecedent of the relative clause: in the English expression a pilot who is experienced, the noun phrase a pilot is the antecedent.