English Clauses - Explanation and Exercises

What is a clause?

A clause is a group of words containing a subject and a verb. A sentence can combine multiple clauses to add detail, and English uses three main types of dependent (subordinate) clause: relative, noun, and adverb clauses.

Relative clauses

A relative clause gives more information about a noun, usually introduced by who, which, that, whose, or a relative adverb (where, when, why).

• The woman who called you is my sister. (describes "the woman")
• This is the house where I grew up. (describes "the house")

Use who for people, which for things, and that for either in informal or restrictive clauses. Whose shows possession: the man whose car was stolen.

Noun clauses

A noun clause functions as a noun in the sentence, often as the subject or object of a verb. It's commonly introduced by that, what, whether, or a question word.

• What she said surprised everyone. (the noun clause is the subject)
• I don't know whether he's coming. (the noun clause is the object)

Adverb clauses

An adverb clause functions like an adverb, describing when, where, why, or under what condition something happens. It's introduced by a subordinating conjunction like because, although, when, if, or while.

• She left early because she was tired. (reason)
• Reduced form: Being tired, she left early. (the same idea, condensed without a subject + verb)

Common mistakes to avoid

• Using "what" instead of "that" in a relative clause: ✗ The book what I read was great. → ✓ The book that I read was great.
• Missing subject in a noun clause: ✗ I don't know is he coming. → ✓ I don't know if he's coming.
• Comma with a restrictive relative clause: ✗ The book, that I read, was great. → ✓ The book that I read was great. (no commas when the clause is essential to identify which book)