An interjection is a short word or phrase that shows emotion. It often stands alone, unconnected to a sentence. Interjections are not normally used in formal writing, but they are common in speech (and therefore informal and fiction writing), where they show emotions such as anger, surprise and interest as well as convey hesitation.

Typical interjections are:
1. Ah! Er. Hey. Ouch! Umm.
2. My God! Bloody hell!
3. Hey! Don't be so lazy!
4. Well, let's think about it.
5. Ouch! That hurts!