"Stop!," "Come here!," and "Look out!" are all examples of the imperative form. You can use the imperative form to give an order, a warning, or some advice.
To form the imperative, use the infinitive form of the verb without "to." To make a negative imperative, put "do not" or "don't" in front of the verb, as in, "Don't touch that!"
The imperative is formed the same for all subjects (you, he, we, they), but you can include yourself in the imperative by adding "Let's," as in, "Let's go for a swim."
If you want to be more polite when using an imperative, just add "please." For example, "Please, leave me alone. I'm trying to learn English!"
Imperative Form Lessons: