Does the contraction "might've" exist?

Question

From what I've found, some spell checkers say it's incorrect while others ignore it. At the same time some people say it's wrong and others disagree.

Some websites indicate it as a contraction, and over 1 million sites use it. But at the same time, that doesn't make it right.

My question is, is it grammatically correct? Is it different in certain parts of the world?

Thanks,
Ken

Please provide sources if possible.

Answer 1

Must've isn't in the dictionary so i doubt it is a proper contraction but there's a book called "It Must've Been Something I Ate" maybe Must've is just slang

Answer 2

I don't have any sources, but I feel like "might've" is just popular slang for "might have". I don't think it's an official word, and it's not showing up on Merriam-Webster's website. To be safe, especially if you're using it in a paper or something to be published, is just to write ot "might have".

Answer 3

I have head might've used quit often. It is common west of the Mississippi. I think that it is indeed gramatically correct.

Answer 4

It is only correct to use it in speech. Don't use it in prose. It's like would've, could've, should've, mightn't've, wouldn't've, couldn't've, shouldn't've. You can say it, but don't write it.