An interrogative pronoun is used to ask questions. The interrogative pronouns are "who," "whom," "which," "what" and the compounds formed with the suffix "ever" ("whoever," "whomever," "whichever," and "whatever"). Note that either "which" or "what" can also be used as an interrogative adjective, and that "who," "whom," or "which" can also be used as a relative pronoun.

You will find "who," "whom," and occasionally "which" used to refer to people, and "which" and "what" used to refer to things and to animals.

"Who" acts as the subject of a verb, while "whom" acts as the object of a verb, preposition, or a verbal.

The highlighted word in each of the following sentences is an interrogative pronoun:

Which wants to see the dentist first?

"Which" is the subject of the sentence.

Who wrote the novel Rockbound?

Similarly "who" is the subject of the sentence.

Whom do you think we should invite?

In this sentence, "whom" is the object of the verb "invite."

To whom do you wish to speak?

Here the interrogative pronoun "whom " is the object of the preposition "to."

Who will meet the delegates at the train station?

In this sentence, the interrogative pronoun "who" is the subject of the compound verb "will meet."

To whom did you give the paper?

In this example the interrogative pronoun "whom" is the object of the preposition "to."

What did she say?

Here the interrogative pronoun "what" is the direct object of the verb "say."