Non- defining relative clauses as sentence modifiers

Use:

Use non-defining relative clauses to give extra information about a noun in a sentence, or part of a sentence. The listener or reader does not need this information to understand the sentence.

Relative clauses can define the subject of the sentence:
Miranda, who used to go to the same university as me, is having a baby.

Or the object of a sentence:
We went to a lovely restaurant, where we both had steak.

Or the sentence as a whole.
She gave me some money, which was very nice of her.

Form:

• Always put the relative clause as close as possible to the noun that you are describing.
• Use who to give information about a person, whose to introduce a possession, and which to give information about a thing. Do not use that.
• Use where to give information about a place ONLY if you introduce another subject after where. Otherwise, use which.

We met at Bristol University, where we both studied Biology.
We met at Bristol University, which is in the west of England.

• Who, which, where and whose cannot be omitted in defining relative clauses.
• As non-defining relative clauses are not necessary to understanding the sentence, they are always placed within commas.

The man who lives next to me has five motorbikes.
In this sentence, ‘who lives to me’ is necessary. Without it, the sentence (‘The man has five motorbikes’) is meaningless because it is not clear which man is being talked about. Therefore, commas are NOT necessary.

Tom, who lives next to me, has five motorbikes. 
In this sentence, ‘who lives to me’ is not necessary. Without it, the sentence (‘Tom has five motorbikes’) still has meaning. ‘Who lives next to me’ adds more information, therefore, commas ARE necessary.

Common Mistakes
Some Students do not put the non defining relative clause close to the noun it describes.

The chemicals flow into rivers, which are toxic.  =>  The chemicals, which are toxic, flow into rivers.

Exercise 1: Non Defining Relative Clauses 

Exercise 2: Non-defining Relative Clauses as sentence modifiers 

Reduced relative clauses

A relative clause is a type of subordinate clause introduced by a relative pronoun.

• What is the name of that boy who just walked in?

Here the clause ‘who just walked in’ is an example of a relative clause. It modifies the noun boy. Relative clauses are also called adjective clauses.

Relative clauses are sometimes shortened.

How to reduce a relative clause?

A participle can often be used instead of a relative pronoun and full verb.

Read the sentence given below.

The girl who sits next to Peter is my neighbor’s daughter.

Now when we shorten the relative clause ‘who sits next to Peter’, we get:

The girl sitting next to Peter is my neighbor’s daughter.

Another example is given below.

Who is the girl who is sitting next to your brother?

Now when we reduce the relative clause, we get:

Who is the girl sitting next to your brother?

More examples are given below.

A girl who works at a pub has won a lottery.
A girl working at a pub has won a lottery.

The lady who lives next door throws numerous parties.
The lady living next door throws numerous parties.

Yesterday I read a book which was written by Hemingway.
Yesterday I read a book written by Hemingway.

Most people who were invited to the party didn’t turn up.
Most people invited to the party didn’t turn up.

Anyone who enters the garden without permission will be punished.
Anyone entering the garden without permission will be punished.

Reduced structures can also be used with the adjectives availableand possible.

Please book all the tickets available. (= Please book all the tickets that are available.)

Exercise 1:  (Reduced Relative Clauses)