The exclamation mark (!) should not be used too frequently. It should be used only after real exclamations or interjections and phrases and sentences expressing sudden emotion or wish.

• What a terrible storm!
• How fiercely the wind blows!
• How cold the night is!
• Alas!
• Good luck!

Sometimes the exclamation mark is also used after a short order.

• Get out! I don’t want to see again.
• Shut up! I don’t want to hear a word.

Related posts:

1. Punctuation – Full Stop