Defining and Non-Defining Relative Clauses

Extra information is added to a sentence by defining a noun using relative clauses. These clauses can be of two different types: defining relative clauses and non- defining relative clauses.

Defining relative clauses are used to give concrete information about what is being said or about whom it is being said. Omitting these clauses either makes the sentence meaningless or gives a completely different meaning. Defining relative clauses often immediately follow the noun they describe. To clarify the above statement observes the two sentences below.

•    They are the people who are buying our Mercedes Benz.

•    Did you buy the painting?

In the first sentence we have the pronoun as “who are buying our Mercedes Benz” and “the people” clarifies who is being referred to. But in the second sentence, it is not clear which painting is being referred to.

In spoken English, we often replace the defining clause who/whom with that. Few pointers with relation to defining relative clauses are as follow:

1.    Don’t use commas while writing defining relative clauses.

2.    The relative pronoun is often left out if it is the object of the verb.

3.    Do not use another personal pronoun in the relative clause if the relative pronoun is the subject of the relative clause.

Now let us understand what is non-defining relative clauses. Non- defining relative clauses though add extra information to the sentence but at the same time if they are omitted also it does not harm the meaning of the sentence. For example, Tom bought the painting done by Picasso, the world famous painter.

In the above sentence the world famous painter refers to the non defining relative clause even if this is omitted the meaning does not change since it is a well known fact that Picasso is world famous for his painting.

Non-defining relative clauses are usually separated by comma. Non defining clauses are mostly used in written English whereas defining clauses are used in spoken English. Mostly pronouns are used to introduce a non defining relative clause.