Commands are also known as the imperative form. There is no difference if you give a command to a single person or to a goup of people - the form of the verb is the same. Put the verb in the infinitive form without "to" at the beginning of the sentence, you don't use a subject and end the sentence with an object.

Tell someone to do something:
Put out the rubbish.
Take an umbrella with you.
Turn off the TV.


Negative form: to make commands negative, put "don't" or "do not" before the verb.

Tell someone not to do something:
Don't shout at me.
Don't open the window.
Do not stay out too late.


Polite form: if you want to use the polite form, then add the word "please".

Polite form:
Please don't shout at me.
Please tell me your phone number.
Hand out the books, please.
Help me with the homework, please.


Exercise 1 Exercise 2 Exercise 3