I was reading a passage in Steinbeck's Of Mice and Men and a character, a migrant farmer, says of another character's fighting ability:
"Nobody don't know what Slim can do".
And then a little later, a similar statement:
"Nobody can't tell what a guy'll do".
I'm quite familiar with slangy statements phrased like questions, such as: Don't nobody care, or Don't anybody want to hear that, or Don't anyone feel like talking to you, but the reversal of the first two words–which does not seem to change the meaning–sounds off.
My questions are, are constructions like
Don't nobody/anybody/anyone + verb
Nobody don't + verb
double negatives, and, if so, is that why the pieces (don't, nobody) can be moved around without changing the meaning?