Interrogative sentence- a sentence that asks questions, ends with a question mark(?) . even though a sentence has a question mark, it doesn't mean that its already an interrogative sentence, for ex. can you please close the door? this sentence is an imperative sentence. interrogative sentences can also  use the WH questions:

-Who ex. Who are you?
-What ex. What are you doing?
-Where ex. Where are you from?
-Why ex. Why are you there?
-When ex. When will be the meeting?
- How ex. How did you do that?