Relative clauses

RELATIVE CLAUSES
NON-DEFINING RELATIVE CLAUSES
The information in these clauses is not essential. It tells us more about someone or something, but it does not help us to identify them or it. Compare:
1. Elephants that love mice are very unusual. (This tells us which elephants we are talking about).
2. Elephants, which are large and grey, can sometimes be found in zoos. (This gives us someextra information about elephants - we are talking about all elephants, not just one type or group).
3. John's mother, who lives in Scotland, has 6 grandchildren. (We know who John's mother is, and heonly has one. The important information is the number of grandchildren, but the fact that she lives in Scotland might be followed with the words "by the way" - it is additional information).Punctuation
Non-defining relative clauses are always separated from the rest of the sentence by commas. The commas have a similar function to brackets:
My friend John has just written a best-selling novel.(He went to the same school as me) > My friend John, who went to the same school as me, has just written a best-selling novel.
Relative pronouns in non-defining clauses
| |Person|Thing |Place |
|Subject |who |which | |
|Object |who/whom |which |where ||Possessive |whose | | |


Notes:
1. In non-defining clauses, you cannot use ‘that’ instead of who, whom orwhich.
2. You cannot leave out therelative pronoun, even when it is the object of the verb in the relative clause:
He gave me the letter, which was in a blue envelope.
He gave me the letter, which I read immediately
3. The preposition inthese clauses can go at the end of the clause, e.g.This is Stratford-on-Avon, which you have all heard about.
This pattern is often used in spoken English, but in written or formal English you can...