Exclamation point for emphasis
Use an exclamation point after a word group or sentence to express exceptional feeling or to provide special emphasis.
Misuses of exclamation points
Usually one exclamation point is sufficient to convey emphasis in a passage. Using more than one will dilute the force of them all.
Do not overuse the exclamation point for inappropriate or unnecessary emphasis.
Exercise:
End punctuation
Related topic:
Exclamation point with quotation marks