Class pop quiz

Teacher: What is a Verb?Peter: A Verb is a valve found in bicycle tyre.Teacher: What are you saying?Peter: It is a complete sentence sir.Teacher: Are you mad?Peter: It is a question sir. Teacher: Don't be stupid.Peter: It is an advice sir.Teacher: Stop that nonsense.Peter: It is a command sir.Teacher: You're an idiot.Peter: It is an insult sir. Teacher: Get out of my class.Peter: It is an order sir.Teacher: Oh! Goodness, What a boy!Peter: It is an exclamation sir.Teacher: May God have mercy on you.Peter: It is a prayer sir