When you’re mad, excited, or emotional, you can use interjections to express your feelings in a sentence.
Oh, hey, ouch, aw, hooray, or darn are some examples of interjections. Use an exclamation mark at the end of the sentence if it is expressing strong emotion.
Take a look at the School House Rock video below.
[youtube http://www.youtube.com/watch?v=RhHpJ45_zwM&w=400&h=315]