non-defining relative clauses

A non-defining relative clause gives extra information. You already know who or what the speaker means, so the sentence is complete without it. Commas go around it, and in speech there is a small pause.

Who, which, whose, where

• who for people
• which for things and animals
• whose for "his", "her" or "their"
• where for places

No that

You can't use that in a non-defining clause. Use who or which. You also can't leave the relative word out.

Defining or non-defining

A defining clause tells you which one, so the sentence needs it, and there are no commas. A non-defining clause only adds something, and it has commas.

Which about a whole sentence

Which after a comma can be about everything that came before it.

Common mistakes

• × My brother, that lives in Leeds, is a teacher. → My brother, who lives in Leeds, is a teacher.
• × My brother who lives in Leeds is a teacher. (if you have only one brother) → My brother, who lives in Leeds, is a teacher.
• × She gave me a book, which I read it in one day. → She gave me a book, which I read in one day.