Relative pronouns function as half pronoun and half conjunction. They function as a pronoun because they refer to a previously mentioned noun or pronoun. They also function as a subordinating conjunction by beginning dependent clauses. The main relative pronouns are:
who, whose, whom, which, that
Other forms of relative pronouns include whoever, whomever, whatever, whichever.
When referring to people use who, whose, whom, whoever, and whomever.
When referring to living things other than people and to nonliving things use which.
That can be used for either. Which and who are also used to ask questions about a people when used as interrogative pronouns.
Which teacher was absent?
Who was absent?
Relative Pronouns with Restrictive and Nonrestrictive Clauses
As previously mentioned, relative pronouns function as subordinating conjunctions when they begin a dependent clause.
There are two types of dependent clauses that begin with relative pronouns: restrictive and nonrestrictive.
A restrictive clause is used when the information in the clause is important to the meaning of the overall sentence.
A nonrestrictive clause is used to indicate that the information in the clause is extra information.
The young woman who is standing at the counter was very beautiful.
Alicia May, who is standing at the counter, is very beautiful.
In the first sentence, we don't know which woman is being discussed until the dependent clause - who is standing at the counter - identifies her.
Since the dependent clause is essential to the meaning of the sentence, it does not take commas. In the second sentence, we are told right away who the woman is, so where she is becomes extra information. Therefore, the dependent clause who is standing at the counter is set off by a comma both before and after the clause.
NOTE: Clauses that begin with the relative pronoun that are almost always restrictive clauses, and therefore do not need commas.
Clauses that begin with the relative pronoun which are almost always nonrestrictive, and therefore do need commas.
Each sentence below contains a dependent clause beginning with a relative pronoun; however, all commas have been ommitted for this exercise. Read each sentence and decide if the dependent clause is a restrictive or a nonrestrictive clause. Then, on a sheet of paper, write each sentence. Beside each sentence write YES if the clause is restrictive or NO if the clause is nonrestrictive. Then add commas to the sentences that contain nonrestrictive clauses. To check you answers, click on each sentence.