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
and
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?