Interrogative pronouns are used to ask a question. Usually, there’s no antecedent (if there was, there would be no need to ask the question). The interrogative pronouns are who, which, what, whom, and whose. You’ll usually find interrogative pronouns at the beginning of the sentence.
Who is going on the trip to India?
With whom will you be going to India?
Which house is yours?
What did you do?
Whose pen is this?