Relative pronoun

A relative pronoun marks a relative clause; it has the same referent in the main clause of a sentence that the relative modifies.

An example is the English word which in the sentence "This is the house which Jack built." Here the relative pronoun which marks the relative clause "which Jack built", which modifies the noun house in the main sentence. Which has an anaphoric relationship to its antecedent "house" in the main clause.

In linking a subordinate clause and a main clause, a relative pronoun functions similarly to a subordinating conjunction. Unlike a conjunction, however, a relative pronoun does not simply mark the subordinate (relative) clause, but also plays the role of a noun within that clause. For example, in the relative clause "which Jack built" given above, the pronoun "which" functions as the object of the verb "built". Compare this with "Jack built the house after he married," where the conjunction after marks the subordinate clause after he married, but does not play the role of any noun within that clause.

For more information on the formation and uses of relative clauses—with and without relative pronouns—see Relative clause. For detailed information about relative clauses and relative pronouns in English, see English relative clause.

The element in the main clause that the relative pronoun in the relative clause stands for (house in the above example) is the antecedent of that pronoun. In most cases the antecedent is a nominal (noun or noun phrase), though the pronoun can also refer to a whole proposition, as in "The train was late, which annoyed me greatly", where the antecedent of the relative pronoun which is the clause "The train was late" (the thing that annoyed me was the fact of the train's being late).

In a free relative clause, a relative pronoun has no antecedent: the relative clause itself plays the role of the co-referring element in the main clause. For example, in "I like what you did", what is a relative pronoun, but without an antecedent. The clause what you did itself plays the role of a nominal (the object of like) in the main clause. A relative pronoun used this way is sometimes called a fused relative pronoun, since the antecedent appears fused into the pronoun (what in this example can be regarded as a fusion of that which).

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