Relative Clauses: Introduction

Definition

Relative clauses are a special category of dependent clause. The key feature of a relative clause is that it relates to a noun or idea in the rest of the sentence by using a relative pronoun. Like other pronouns, relative pronouns substitute for a noun group or pronoun. For example:

Mount St. Helens, which is located in the Pacific Northwest, is an active stratovolcano. (which = Mount St. Helens)

Fifty-seven people who were on or near the volcano died. (who = 57 people)

The avalanche that the eruption triggered reduced the summit of the mountain by over 1000 feet. (that = the avalanche)

Relative pronouns can be omitted in some relative clauses, but you can always expand the clause to find where the pronoun belongs. For example:

People [who were] living in Alberta found ash [that was] ejected from the volcano on their cars the next morning.

Since relative clauses are a type of dependent clause, sentences containing relative clauses are considered complex sentences, and relative clauses cannot stand alone as complete sentences in writing.

Form

The relative pronouns are:

that

which

who

whom

whose

In general, that can be used for any referent, who/whom are used for people, and which is used for things. Whose is a possessive pronoun, and is not used frequently.

There are four structures of relative clause, depending on the role that the relative pronoun plays in the clause:

Subject relative clauses (the relative pronoun is the subject of the verb in the relative clause): the person who is standing over there; trees which lose their leaves

Object relative clauses (the relative pronoun is the direct object of the verb in the relative clause): people that he didn’t know (he didn’t know the people); books which I have read (I have read the books)

Object-of-a-preposition relative clauses (the relative pronoun is the object of a preposition in the relative clause): the student that the principal is talking to (the principal is talking to the student); the street which the school is found on (the school is found on the street). Note that the preposition can be moved up to the front of the clause: the student to whom the principal is talking; the street on which the school is found.

Possessive relative clauses (the relative pronoun replaces a possessive in the relative clause, such as its, her, his, or their): drivers whose cars are illegally parked (their cars are illegally parked); the dog whose owner was sick (the dog’s owner was sick).

A key focus when teaching or analyzing relative clauses is the punctuation. Clauses with commas (non-restrictive relative clauses) have a different meaning from clauses without commas (restrictive relative clauses).

The eruption which happened in 1980 was the deadliest in U.S. history.

The eruption, which happened in 1980, was the deadliest in U.S. history.

Function

Relative clauses have two very different functions and are discussed in separate sections:

Embedded, or restrictive, relative clauses are part of the noun group and modify the meaning of the referent noun.

Nonrestrictive relative clauses expand on the meaning of the entire sentence without changing the meaning of the referent noun.