An interrogative pronoun is a type of pronoun used to ask questions. The most common interrogative pronouns are who, whom, whose, what, and which. These pronouns help to gather information about people, objects, or ideas in a sentence. For example, in the question "Who is coming to the party?" the word "who" is the interrogative pronoun. Interrogative pronouns can also be used in indirect questions. For instance, in the sentence "I wonder what he is doing," "what" serves as the interrogative pronoun. These pronouns are essential for forming questions and seeking clarification in communication.