3. Interrogative Pronouns - who (whose, whom), which, and what

Interrogative pronouns are pronouns that are used in asking questions. The interrogative pronouns are: who (whose, whom), which, and what. An interrogative pronouns also has another function to perform in the sentence, just as any other pronoun has. It may be the subject of the sentence, or it may be the object of the verb or of a preposition.