Sun doesn't / don't shine? [duplicate]
I'm curious about the grammar in the vulgar idiom "Where the sun don't shine".
Why is there a don't instead of doesn't? The latter strikes me as the correct grammatical form, but I'm not sure.
Solution 1:
It is an informal AmE usage:
Don’t vs doesn’t
Don't is occasionally used in American English speech and in historical writing as a contraction of does not (as in, "He don't know where he is going."), but this use is now considered improper and should be avoided.
(Merrian Webster)