GRAMMAR - RELATIVE CLAUSES

RELATIVE PRONOUN	USE	EXAMPLE
WHO	Subject or object pronoun for people.	I told you about the man who works in my office.
WHICH	Subject or object pronoun for animals, and things.	Do you see the dog which is sleeping on the floor?
WHOSE	Possession for people animals and things.	Do you know the girl whose uncle is a lawyer?
WHOM	Object pronoun for people.	I was asked out by the boy whom I met at the party.
THAT WHEN WHERE	Subject or object pronoun for people, animals and things in defining relative clauses (who or which are also possible, but that is more informal). To refer to time. / That is also possible. Location of people animals and things.	I love the clock that hangs on this wall. The year when/that we first met was 1999. That is the University where I did my degree.

1. DEFINING RELATIVE CLAUSES Level: lower intermediate

- Defining relative clauses give detailed information defining someone or something. Defining relative clauses are never put in commas.

- Situation: Mary is in a room with three boys. One boy is talking to Mary and you ask somebody whether she knows that boy. This relative clause defines or identifies which of the three boys you mean. 

Do you know the boy who is talking to Mary? 

- Defining relative clauses are used in definitions: A singer is someone who sings.

- Object pronouns (WHO, WHICH) in defining relative clauses can be substituted by THAT. WHEN can be omitted and substituted by THAT; WHERE is seldom omitted: The man who/that opened the door is my neighbour. The student (who/whom) we met last week is extremely friendly.

- When the verbs in the main clause and the relative clause have a different subject, WHO/WHICH/THAT can be omitted: She is the woman to whom you talked. (FORMAL)   She is the woman (who) you talked to. (INFORMAL)

 2. NON-DEFINING RELATIVE CLAUSES

- Non-defining relative clauses give additional information on something, but do not define it. Non-defining relative clauses are always put in commas.

- Situation: Mary is in a room with only one boy. The two are talking to each other and you ask somebody whether she knows this boy. This relative clause is non-defining because in this situation it is evident which boy you mean. 

Do you know the boy, who is talking to Mary?

-  In non-defining relative clauses, WHO/WHICH cannot be replaced with THAT (that is never used in these clauses): That man, who (that) opened the door, is my neighbour.

- Object pronouns in non-defining relative clauses cannot be omitted: Joe, who/whom we saw yesterday, is nice.