A relative pronoun is a pronoun that marks a relative clause within a larger sentence. It is called a relative pronoun because it relates to the word that it modifies. In English, relative pronouns are who, whom, which, whose, and that.

A relative pronoun links two clauses into a single complex clause. It is similar in function to a subordinating conjunction. Unlike a conjunction, however, a relative pronoun stands in place of a noun. Compare:

(1) This is a house. Jack built this house.

(2) This is the house that Jack built.

Sentence (2) consists of two clauses, a main clause (This is the house) and a relative clause (that Jack built). The word that is a relative pronoun. Within the relative clause, the relative pronoun stands for the noun phrase it references in the main clause (its antecedent), which is one of the arguments of the verb in the relative clause. In the example, the argument is the house, the direct object of built.

Other arguments can be relativised using relative pronouns:

Subject: Hunter is the boy who kissed Monique.

Indirect object: Hunter is the boy to whom Monique gave a gift.

Adpositional complement: Jack built the house in which I now live. (and similarly with prepositions and prepositional phrases in general, eg These are the walls in between which Jack ran.)

Possessor: Jack is the boy whose friend built my house.

In some languages, such as German and Latin, which have noun declensions, the relative pronoun will often agree with its antecedent in gender and number, while the case may indicate its relationship with the verb in the relative clause. In other languages, the relative pronoun is an invariable word.

The words used as relative pronouns are often words which originally had other functions: for example, the English which is also an interrogative word. This suggests that relative pronouns might be a fairly late development in many languages. Some languages do not have relative pronouns.

In English, different pronouns are sometimes used if the antecedent is a human being, as opposed to a non-human or an inanimate object (as in who/that).

(5) This is a bank. This bank accepted my identification.

(6) She is a bank teller. She helped us open an account.

With the relative pronouns, sentences (5) and (6) would read like this:

(7) This is the bank that accepted my identification.

(8) She is the bank teller who helped us open an account.

In sentences (7) and (8), the words that and who are the relative pronouns. The word that is used because the bank is a thing; the word who is used because 'she' is a person.

[edit] See also

• For specific discussion of English usage: English relative clauses or English grammar.
• Relative pronouns in Spanish