Relative clauses

The point

Who is for people. Which is for things. Whose marks possession. A defining clause has no commas and tells you which one. An extra clause has commas and only adds a fact about someone already named.

Form and use

A relative clause adds information about a noun. A defining clause tells you which person or thing. It has no commas. A non-defining clause adds extra information about a noun that is already clear. It needs commas. The choice of pronoun follows the noun and the role inside the clause.

Pronouns: who — people, subject whom — people, object, formal which — things that — people or things, defining clauses only whose — possession where — places when — times why — reasons, often after reason Which can also point back at a whole clause: the file was late, which annoyed the client.

In a defining clause, who, which, or that can introduce it. If the pronoun is the object, you may omit it: the report we sent. Do not use that in a non-defining clause, and do not drop the pronoun there. Commas mark the extra clause: Mina, who owns the file, replied. Without commas, who owns the file would limit which Mina you mean.

Two contrasts cause most errors. People take who, not which: the person who called. Possession takes whose, not who: the firm whose note was late. A thing takes which or that, not who. After a comma, use who for a person and which for a thing, never that. Whom is optional and formal when the person is the object: the client whom we emailed.

Don't translate it like this

A person takes who, not which.

Short examples