Relative Pronouns

In order to explain the relative clauses, I searched on the web for more information and I came across this text in the British Council website (HERE). 

Relative clauses – defining relative clauses

Relative clauses add extra information to a sentence by defining a noun. They are usually divided into two types –defining relative clauses and non-defining relative clauses.

Defining relative clauses

Look at this sentence:

• The woman who lives next door works in a bank.

‘who lives next door’ is a defining relative clause. It tells us which woman we are talking about.

Look at some more examples:

• Look out! There’s the dog that bit my brother.
• The film that we saw last week was awful.
• This is the skirt I bought in the sales.

Can you identify the defining relative clauses? They tell us which dog, which film and which skirt we are talking about.

Relative pronouns

Relative clauses are often introduced by a relative pronoun (usually who, which, that, but when, where and whoseare also possible)

With defining relative clauses we can use who or that to talk about people.

• She’s the woman who cuts my hair.
• She’s the woman that cuts my hair.

And we can use that or which to talk about things.

• The dog that bit my brother.
• The dog which bit my brother.

It is also sometimes possible to omit the relative pronoun.

• This is the skirt that I bought in the sales.
• This is the skirt whichI bought in the sales.
• This is the skirt I bought in the sales.

In this sentence ‘skirt’ is the object of the verb (buy). ‘I’ is the subject. When the relative pronoun is the object, it can be omitted.

• The film we saw last week was awful.
•  BUT The dog bit my brother. This is not possible because the dog is the subject of the verb, ‘bite’.

Relative clauses - non-defining relative clauses

Relative clauses add extra information to a sentence by defining a noun. They are usually divided into two types –defining relative clauses and non-defining relative clauses.

Non-defining relative clauses

Look at this sentence.

• My grandfather, who is 87, goes swimming every day.

‘who is 87’ is a non-defining relative clause. It adds extra information to the sentence. If we take the clause out of the sentence, the sentence still has the same meaning.

Look at some more examples.

• The film, which stars Tom Carter, is released on Friday.
• My eldest son, whose work takes him all over the world, is in Hong Kong at the moment.
• The car, which can reach speeds of over 300km/ph, costs over $500,000.

Non-defining relative clauses add extra information to sentences.

Defining or non-defining?

Remember that defining relative clauses are used to add important information. The sentence would have a different meaning without the defining relative clause.

• I’m going to wear the skirt that I bought in London. The defining relative clause tells us which skirt.
• The skirt, which is a lovely dark blue colour, only cost £10. The non-defining relative clause doesn’t tell us which skirt – it gives us more information about the skirt.

Non-defining relative clauses can use most relative pronouns (which, whose etc,) but they CAN’T use ‘that’ and the relative pronoun can never be omitted.

• The film, that stars Tom Carter, is released on Friday.

Non-defining relative clauses are more often used in written English than in spoken English. You can tell that a clause is non-defining because it is separated by commas at each end of the clause.

This information can be read HERE.

Now, a tip: defining or non-defining clause?? 
When you read the sentence and take the defining clause away, the sentence no longer makes sense. On the contrary, if you take the non-defining clause away, the rest of the sentence makes sense. 




Have a look at this link and complete the blanks of the exercise:

http://www.englisch-hilfen.de/en/exercises/pronouns/relative_pronouns2.htm

http://www.ego4u.com/en/cram-up/grammar/relative-clauses (here you have an explanation about this and in the end of the page you have got links for more exercises.)