What are interjections? Also known as an exclamation, an interjection offers an emotion to a sentence. Many times, it stands by itself, as shown below. Keep in mind, that while interjections often are followed by an exclamation point, if the feeling isn't very strong, it can also be followed by a comma.
Wow! That concert was awesome.
Interjection = Wow!
Hey! Get your clothes put away.
Interjection = Hey!
Yes, I'd like some more.
Interjection = Yes,
This is a simple rule to learn, so . . .
Yeah! This lesson is over.