An interrogative sentence is a type of sentence that poses a question and ends with a question mark. Two examples of an interrogative sentence are as follows: "Do you drink coffee in the morning?" and "How many times have you been to San Francisco?"
An interrogative sentence's job is to ask a question, as opposed to a declarative sentence, which makes a statement such as "I drink coffee in the morning," and an imperative sentence, which makes a command, such as "Go to bed." Another example of an interrogative sentence is, "How often do you and your husband go on vacation?"