Interrogative pronouns

The interrogative pronouns who, whom, and whose are used only for reference to people. The interrogative pronouns which and what are used for reference to things.

	subject	object	possessive
people	who	whom	whose
things	which what	which what

Interrogative pronouns allow us to build a question around the thing that the pronoun refers to. See WH- words, where they are explained more generally under the heading of WH- words.

Who is dancing with Lucy?
Which of these books would you recommend?
What do you do when you’re on holiday?
Whose are these clothes?

Who is used to ask questions about people in general.

Who is that man over there?
Who did this?
Who controls the day-to-day running of the business?

What is used to ask questions about things in general when the answer is an open one. What can be either a subject or an object in a clause.

What happened next?
What did you have for lunch?

Which is used ask for identification of a particular person or a particular thing in a group.

Which do you prefer, working in theatre or film?
Which is your favourite Simpsons episode?

Whose is the possessive form of the pronoun. It is used when a person is the possessor.

Whose is that sports car outside?
Whose side are you on?

Whom is the object form of who. It is a very formal word and one which most speakers avoid using in casual conversation, when who could be used instead. When writing, however, it is usual to use whom.

Informal
Who do you have in mind?
Who were you speaking to?

Formal
Whom have you in mind?
To whom were you speaking?

The object forms of the interrogative pronoun are used after a preposition. In informal and everyday usage, you can place the preposition at the end of the clause.

Who does this belong to? Informal
To whom does this belong? Formal