Relative clauses

Relative clauses give extra information about something or someone in the main clause.


Defining relative clauses

Defining relative clauses contain information which is essential for our understanding of the whole sentence.
The woman who normally comes to clean our windows is on holiday this month.
In each case, the relative clause identifies which person or thing is being talked about.

Features of defining relative clauses.
- No comas are required either at the beginning or the end of the relative clause.
- That can be used instead of who for people and which for things, particulary in spoken English.

	For people	For things
Subject	who/that	which/that
Object	who/that/whom	which/that
Possessive	whose	whose

*whom is more formal than who

- The relative pronoun can be omitted if it is the object of the verb in the relative clause.
I'm enjoying the book (which/that) you lent me.
- The realtive pronoun cannot be omitted if it is the subject of the verb in the relative clause.
That's the shop assistant who/that served me the last time I came here.


Non-defining relative clauses.

Non-defining relative clauses contain information which is not essential for our understanding of the sentence. We can identify which person or thing is being talked about without the information in the relative clause.
Their new palace, which has five bedrooms and a games room, is much larger than their previous one.

Features of non-defining relative clauses
- Commas are required both at the beginning and the end of the relative clause (except when the end of the relative clause is also the end of the sentence).
- That cannot be used in place of who or which.

	For people	For things
Subject	who	which
Object	who/whom	which
Possessive	whose	whose

- Relative pronouns cannot be omitted from non-defining relative clauses.
Her english teacher, who/whom everyone in the class adored, announced that he was leaving the school.
- Non-defining relative clauses are more common in written English.
- Which can be used in non-defining relative clauses to refer to a whole clause.
No one phoned him on his birthday, which made him feel rather depressed.


Relative clauses and prepositions

Prepositions usually come at the end of defining and non-defining relative clauses.
In defining relative clauses the relative pronoun is usually omitted.
The town I grew up in has changed a lot since I left.
In non-defining relative clauses the relative pronoun is never omitted.
Mark Ralf, who I used to work with, lives in Berlin now.

In more formal English, prepositions often come before the relative pronouns whom for people and which for things (in which case the pornoun cannot be omitted).
The head waiter, to whom we addressed our complaint, was not particularly helpful.


Relative adverbs: where, when and why.

Where, when and why can be used in relative clauses after nouns which refer to a place, a time or a reason.

Where has the meaning "in/at which"
Defining: They've booked a week in that campsite where we stayed last year.
Non-defining: He's in Southlands Hospital, where you were born.

When has the meaning "on/in which" and can be omitted in defining relative clauses.
Defining: Do you remember that day (when) we went to Berlin and it snowed?
Non-defining: I'm going on holiday in October; when most people are back at work.

Why has the meaning "for which" and can be omitted in defining relative clauses.
Defining: The reason (why) I'm phoning is to ask you for Anne's address.