A relative clause is a clause which starts with a relative pronoun.
- who (for people and sometimes pets): The man who is standing there is my brother.
- which (for things and animals): The coat which I have bought is very warm.
- that (for people, things and animals; it’s more informal than who or which): The shop that was here in the past has closed down.
- whose (used for showing possession): The girl whose bag is on the floor has gone home. The car whose tire is pierced is mine.
- whom (used instead of who if who is the object*; it’s more formal than who): I see the person to whom I would like to speak.
*A relative pronoun can be the subject or the object of a relative clause:
The other day I went to the restaurant which had just opened. (subject = the restaurant had just opened)
The other day I went to the restaurant which your brother had just opened. (object = your brother had opened the restaurant).
We usually put the relative clause as close as possible to the noun it refers to. Otherwise, the meaning may be unclear:
You can take this course, which many of my friends have recommended, at the local language school. (if “which many of my friends have recommenced” goes after “school”, it sounds like the friends have recommended the school, not the course)
Relative clauses can perform a few different functions:
- commenting on the whole of the main clause (non-defining): I have splashed out a thousand dollars on a gift, which is unusual for me.
- identifying something in the main clause (defining**): I like the album that the singer has released.
- giving extra information about something in the main clause (non-defining): The car, which cost me a fortune, is really cool.
**In defining relative clauses we can omit the relative pronoun when it’s the object of the relative clause, but we CANNOT omit it when it’s the subject:
The other day I went to the restaurant had just opened. I like the album the singer has released.
In American English that is more common than which or who in defining relative clauses (Source: My GrammarLab Advanced, 2012 by M.Foley and D.Hall).
NON-DEFINING RELATIVE CLAUSES
We don’t use that to introduce a non-defining relative clause:
The car, that cost me a fortune, is really cool; I have splashed out a thousand dollars on a gift, that is unusual for me. Any other relative pronoun can be used for the introduction:
I read a business report while I was waiting at the station, which was very boring.
Mary’s father, who is very strict, didn’t let her come to the party.
His strongest criticism is reserved for his father, whom he disliked intensely.
Stevenson, whose short film won a few awards, was chosen to direct the movie.
COMMAS & INTONATION
- The members of the team who had sponsors set out for Japan. This answers the question “Which members of the team set out for Japan?” The answer is “the ones who had sponsors.” This defines particular members and this means that some other members of the team probably didn’t set out for Japan.
- The members of the team, who had sponsors, set out for Japan. This means “The members of the team set out for Japan.” It’s not about particular members but all of them. Therefore, the whole team set out for Japan.
In written English commas show the differences. In speech a falling intonation shows the beginning of a non-defining relative clause. There is also a short pause before it. When it is finished, the pitch of the speaker’s voice rises again.