Look at the italicized group words in the following sentence.
The house that I live in belongs to my father. (Which house?)
Here the group of words that I live in says something about the noun house. Therefore it does the work of an adjective. It also contains a subject and a predicate of its own which means that it is a clause. And because it does the work of an adjective it is called an adjective clause.
Definition
An adjective clause is a group of words which contains a subject and a predicate of its own and does the work of an adjective.
More examples are given below.
- I know the place where he was born. (Here the adjective clause where he was born qualifies the noun place.)
- The house that you see over there is a hundred years old. (Here the adjective clause that you see over there modifies the noun house.)
Now study the pair of sentences given below.
- I met a girl with blue eyes.
- I met a girl whose eyes were blue.
In sentence 1, the group of words with blue eyes says something about the noun girl. It makes sense, but not complete sense. It is therefore called an adjective phrase.
In sentence 2, the group of words whose eyes were blue also says something about the girl. It has a subject and a predicate of its own. Therefore it is called an adjective clause.
We further notice that the adjective clause ‘with blue eyes’ is equivalent to the adjective clause ‘whose eyes were blue’ and can therefore be replaced by it.