In positive commands, we use the INFINITIVE VERB without "to"
and without SUBJECT:
· Go!
· Look at me.
· Help!
· Be quiet.
· Be good.
· Stop talking.
· Sit down.
· Shut up!
· Call the police!
· Wait a minute.
In negative commands, we use: "do" + "not" + INFINITIVE VERB
without "to" and without SUBJECT:
· Don't wear that stupid hat.
· Do not sign your name with a pencil. Sign with a pen.
· Don't walk on the grass.
· Don't act like an idiot.
· Don't yell at me!
Of course there are many words to soften a command:
Please, excuse me, pardon me, thank you, thanks
· Please repeat the question.
· Please speak more slowly. --Thank you.
· Tell me please, what time is it? --Thank you.
· Excuse me, pass me the salt please. --Thanks
· Excuse me, come this way please.
· Pardon me, please don't smoke in the elevator.
· Pardon me, please speak quietly, remember that you are in a hospital.
· Hold on please.
source: http://www.easyenglish.com/lesson.asp?dont.txt
