Interrogative pronouns are used in asking questions. There are five of them, all of which begin with wh-: who, whom, whose, which, what. Who is used for people while which and what are used for things. These pronouns do not have gender.

The following sentences show interrogative pronouns being used to ask questions:

Examples:

Using who:

  • Who are you shouting at?
  • Who is that person?

Using whom:

  • Whom are you staying with?
  • Whom do you wish to speak to?

Using what:

  • What is your address?
  • What are you going to do?

Using which:

  • Which of these colours do you like?
  • Which do you think is better?

Using whose:

  • Whose is that car?
  • Whose are those children?
 

Who is the subject pronoun while whom is the object pronoun. See the following sentences:

'Case' examples:

Subjective case

  • Who ate my pizza?
  • Which costs more than my car?
  • What caused her sickness?

Possessive case

  • Whose baby is crying loudly?
  • Which of the author's books have you read?
  • What does he complain of the whole day?

Objective case

  • Whom did you borrow that book from?
  • Which did you throw away?
  • What have you planned to do this weekend?
 

Who as mentioned above is the subject pronoun. It can however be used as the object of a verb.

  • Who opened the gate? (as the subject)
  • Who are you inviting to your party? (as the object)
  • Who is she smiling at? (as the object of a preposition)
 

Whom is used as the object of a preposition. Prepositions used here: about, of, to.

  • Whom are you worried about?
  • Whom are you drawing pictures of?
  • Whom have you addressed the letter to?
 

The preposition can come at the beginning of the interrogative pronoun.

  • About whom are you worried?
  • Ofwhom are you drawing pictures?
  • To whom have you addressed the letter?
 

It's wrong to repeat the preposition as in the following interrogative pronoun.

  • Incorrect: To whom have you addressed the letter to?
 

Whom cannot be used as the subject (of a verb).

  • Incorrect: Whom beat him up yesterday?
  • Correct: Who beat him up yesterday?