Relative pronouns

The relative pronouns are the words who, whom, which, and that.

	person	thing
subject object	who or that whom or that	which or that which or that
possessive	whose	whose

The function of a relative pronoun is to link a subordinate clause to a main clause.

He might lose his job, which would be disastrous.
She promised to give away all the money, which was a bit rash.

A subordinate clause introduced by a relative pronoun is called a relative clause.Relative pronouns refer back to a noun phrase or pronoun that has just been mentioned. All relative pronouns must come as near as possible to the start of the clause that they are in. The only words that normally come before them in the clause are prepositions or conjunctions.The choice of relative pronoun is influenced as follows:

That as a relative pronoun never has a preposition before it.

That is a kind thought, for which I am most grateful.
This is the person that Annie was talking about.
This is the person about whom Annie was talking.

Which is not used for human subjects or objects.

That is the car which she has just bought.
I have found a ring which you will love.

Who and whom are restricted to human subjects or objects.

He introduced me to his friend, who had just returned from China.
I liked the actor who was playing Oedipus.

In defining relative clauses (see Relative clauses), that can be used instead of which and is sometimes used instead of who or whom.

I have found a ring which you will love.
I have found a ring that you will love.
She is the girl who was at Sam’s party.
She is the girl that was at Sam’s party.

The object form of the relative pronoun is used as the object of a verb or a preposition, but because whom is very formal, it is not often used: in everyday English, who is usually used instead.

The late Principal of the College, whom we all remember with affection, left this bursary in her will.

I discovered who he was visiting. neutral
I discovered whom he was visiting. formal

In informal writing and speech, any preposition is placed after the verb phrase instead of before the relative pronoun.

The girl who Brian was talking to seemed nervous.
The people who he had been working for that summer had offered him a permanent job.

In informal and spoken English, a defining relative pronoun referring to the object of the clause may be left out entirely.

He is the person (that/who/whom) Annie was talking about.
That is the car (which/that) she has just bought.