A relative pronoun comesat the beginning of a relative clause. A relative clause is a subordinate clause that tells us more about the noun in the main clause. The relative clause comes immediately after the noun. Relative pronouns are that, which, who, whom, whose, whatever, whichever, whoever, whomever, etc. That and which refer to animals and things. That may also refer to people. We use the relative pronouns who and whom for people, and whose for people and things.
- I know the dog that bit my cat.
In the above sentence, the relative pronoun is that and it introduces the relative clause (in bold). ‘I know the dog’ is the main clause. The relative clause that bit my cat tells us something about the noun dog.
We use that and which in almost the same way as we use who, but they refer to things, not people. There is a difference in using which and who. After which, we can use a verb, a pronoun or a noun. After who, we usually use a verb.
- That was the camera, which cost five hundred dollars. (Before verb)
- That was the camera, which he bought. (Before pronoun)
- That was the camera, which John liked. (Before noun)
- Who lives in that haunted castle? (Before verb)
- That is the man, who is my dad's best friend. (Before verb)
We use who as a relative pronoun to refer to people. In the last sentence, who refers to man which is a noun in the main clause, and it begins the relative clause who is my dad’s best friend. We can use who to join two sentences.
- The man is an artist. He drew those pictures.
- The man who drew those pictures is an artist.
We use whom to make a statement about human beings. It is used in place of who (a) when it is the object of a verb or (b) when it comes after a preposition.
- The man whom they caught was sent to prison.
- The man to whom you should speak is the manager. / The man whom you should speak to is the manager.
We use whose to show possession or relationship for both people and things.
- That is my uncle whose wife has left him.
- The door whose knob has come out needs a new one.