How to Use a Relative Clause

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Relative clauses are also referred to as adjective clauses. They are used to modify a noun, which is either the subject or the object of a sentence. For example:

She is the woman who he met at the party last week.

I bought a book which was published in Germany last year.

"Who he met at the party" is a relative clause that describes the subject of the sentence, which is "woman." "Which was published in Germany" describes the object of the verb "bought."

Intermediate-level English learners need to learn relative clauses to improve their writing skills in order to begin crafting more complex sentences. Relative clauses help connect two separate ideas which might otherwise be expressed in two separate sentences. Examples:

That is the school.

I went to that school as a boy.

  • That is the school (that) I went to as a boy.

That's a beautiful car over there!

I'd like to buy that car.

  • I'd like to buy that beautiful car over there.

How to Use Relative Clauses?

Use relative clauses to provide extra information. This information can either define something (defining clause) or provide unnecessary but interesting added information (non-defining clause).

Relative clauses can be introduced by:

  • A relative pronoun: who (whom), which, that, whose
  • No relative pronoun
  • Where, why, and when instead of a relative pronoun

You need to consider the following when deciding which relative pronoun to use:

  • Is the subject or object or possessive of a relative clause?
  • Does it refer to a person or an object?
  • Is the relative clause a defining or non-defining relative clause?

Relative clauses are often used in both spoken and written English. There is a tendency to use non-defining relative clauses mostly in written, rather than in spoken, English.

The Importance of Defining Relative Clauses

The information provided in a defining relative clause is crucial in understanding the meaning of the sentence.

Examples: 

  • The woman who lives in apartment number 34 has been arrested.
  • The document that I need has "important" written at the top.

The purpose of a defining relative clause is to clearly define who or what we are talking about. Without this information, it would be difficult to know who or what is meant.

Example: The house is being renovated.

In this case, it is not necessarily clear which house is being renovated.

Non-Defining Relative Clauses

Non-defining relative clauses provide interesting additional information which is not essential to understanding the meaning of the sentence.

Example: Mrs. Jackson, who is very intelligent, lives on the corner.

Correct punctuation is essential in non-defining relative clauses. If the non-defining relative clause occurs in the middle of a sentence, a comma is put before the relative pronoun and at the end of the clause. If the non-defining relative clause occurs at the end of a sentence, a comma is put before the relative pronoun. In defining relative clauses, there are no commas.

Examples: 

  • Children who play with fire are in great danger of harm.
  • The man who bought all the books by Hemingway has died.

Generally, "who" and "which" are more usual in written English, whereas "that" is more usual in speech when referring to things.

Relative Pronouns and Defining Relative Clauses

Examples: 

  • That's the boy (who, whom) I invited to the party.
  • There's the house (that, which) I'd like to buy.

Relative Pronouns Used as a Possessive

Examples: 

  • He's the man whose car was stolen last week.
  • They were sure to visit the town whose location was little-known.

It is preferable to use that (not which) after the following words: all, any(thing), every(thing), few, little, many, much, no(thing), none, some(thing), and after superlatives. When using the pronoun to refer to the object, "that" can be omitted.

Examples: 

  • It was everything (that) he had ever wanted.
  • There were only a few (that) really interested him.

Examples: 

  • Frank Zappa, who was one of the most creative artists in rock 'n roll, came from California.
  • Olympia, whose name is taken from the Greek language, is the capital of Washington State.

Relative Pronouns and Non-Defining Relative Clauses

Examples: 

  • Frank invited Janet, who (whom) he had met in Japan, to the party.
  • Peter brought his favorite antique book, which he had found at a flea market, to show his friends.

"That" can never be used in non-defining clauses.

Possessive in Non-Defining Relative Clauses

Example: 

  • The singer, whose most recent recording has had much success, was signing autographs.
  • The artist, whose name he could not remember, was one of the best he had ever seen.

In non-defining relative clauses, "which" can be used to refer to an entire clause.

Example: 

  • He came for the weekend wearing only some shorts and a t-shirt, which was a stupid thing to do.

After numbers and words like "many," "most," "neither," and "some," we use "of," "before," "whom," and "which" in non-defining relative clauses. 

Example: 

  • Many of those people, most of whom enjoyed their experience, spent at least a year abroad. Dozens of people had been invited, most of whom I knew.