1. The form of the Imperative
We use the infinitive to form the Imperative.
Affirmative sentences	Negative sentences
Open your books at page 34.	Don't open your books at page 44.
Come here.	Don't come now.
Clean the bathroom.	Don't clean the living room.
Help your father.	Don't play on the computer.
Use the exclamation only when you want to make an exclamation, e.g. Stop! Help!
2. The Imperative with let's
Affirmative sentences	Negative sentences
Let's ask the teacher.	Let's not ask the teacher.