An interrogative is a type of sentence that asks a question. It is designed to elicit information and typically begins with words like who, what, where, when, why, or how. Interrogative sentences often end with a question mark, indicating that a response is expected. In English grammar, interrogatives can be formed in various ways, including yes/no questions and open-ended questions. For example, "Is it raining?" is a yes/no question, while "What time is it?" is an open-ended interrogative. Both types serve the purpose of seeking clarification or information.