Grammar: The Exclamation Mark [ ! ]

 

The exclamation mark is exclusively a feature of quoted speech and informal English. It has no place in academic writing.

Its uses are two. The first is with imperatives, but only if they are truly commands –

       Go!
       Wait!
       Help!
       Do as you’re told!
       Keep off the grass!
       Stop picking your nose!

This includes imperatives expressed as wishes      

       I wish you’d stop doing that!

but not imperatives expressed as questions      

       Why don’t you leave me alone?

Exclamation marks are not used with imperatives that are contextually requests, invitations or statements of advice –

       Give me your number again.
       Have another beer.
       Help yourself.
       Don’t mention it.
       Vote for Jones.

The second use of the exclamation mark is with interjections (words or expressions of emotion)      

       Ugh!
       Hmm!
       Ouch!
       Oh dear!
       Oh no!
       Really!
       Good heavens!

Informally, of course, the exclamation mark may be used more freely to illustrate surprise or to draw attention to something important –

      I didn’t find out myself till last week!

      The meeting has been brought forward from the 19th to the 12th!

But like question marks, one is quite sufficient.