A relative clause is a clause that generally modifies a noun or noun phrase, and is introduced by a relative pronoun (which, that, who, whom, whose), a relative adverb (where, when, why) or a zero relative. They are also known as an adjectival clause.
For example:
- Can I have the pencil that I gave you this morning?
- Yesterday I called our friend Julie, who lives in New York.
- In the summer I'm going to visit Italy, where my brother lives.
There are two types of relative clause:
1. restrictive (or defining) relative clauses
2. non-restrictive (or non-defining) relative clauses A restrictive or defining relative clause, as a name suggest, provides some essential information about the noun to which it refers. So, it cannot be left out of the sentence without affecting the meaning.
For example: - It reminded him of the house that he used to live in. - The coat that/which Dan had on yesterday was new. - The people who / that live on the island are very friendly.
Non-definite relative clause, also called non-identifying relative clauses or non-restrictive relative clauses give additional information on something, but do not define it. That information can be left out without affecting the meaning or structure of the sentence, because a non-defining relative clause gives us some extra information about something, and we don't need this information to understand the sentence.
For example:
- My sister, who I live with, knows a lot about cars.
- I really love the new Chinese restaurant, which we went to last night.
- Last week I bought a new computer, which I don't like now.
They have three main characteristics:
a) In speech the intonation is different from the noun they qualify
b) In spelling they are separated by commas
c) In meaning they are not essential to the meaning of the clause.
A non-defining relative clause usually has a comma in front of it and a