Interrogative pronouns are words used to ask questions about people or things. The main interrogative pronouns in English are who, whom, whose, what, and which. They help gather information by replacing nouns in questions, making it easier to inquire about specific subjects. For example, you might ask, "Who is coming to the party?" or "What is your favorite book?" In these sentences, who and what are the interrogative pronouns that seek information. Using these pronouns allows for clear and direct questioning in conversations and writing.