Colloquialisms are words and phrases that are part of our everyday speech, but that are not part of our formal language. Colloquialisms may include slang terms, but a hallmark of colloquialism is that these statements are understood by all people in a specific location or geographic region (as opposed to some slang terms that are only understood by one age group).
Colloquialisms can make writing more believable--the characters sound like actual people. However, colloquialisms are not appropriate for formal writing-such as academic essays.
I am going to have a conniption fit! (in other words, freak out--which is another colloquialism)
Don't cause a ruckus.
Examples of Colloquialisms in Literature
From Huckleberry Finn, by Mark Twain:
What's the use you learning to do right, when it's troublesome to do right and it ain't no trouble to do wrong, and the wages is just the same?
From The Catcher in the Rye, by J.D. Sallinger:
When you're dead, they really fix you up . I hope to hell when I do die somebody has sense enough to just dump me in the river or something.
Literary Terms Examples