Let's begin with a sentence such as:
We can't do this any more.
This is the most standard form and grammatically perfect. But I have also seen or heard many times in some informal occasions (maybe that is a fad), esp. in pop lyrics, some sentences like this one
We can't do this no more
or even
Ain't got no money in my pocket
I'm most aware that such a "fad" is grammatically incorrect and definitely unacceptable in formal occasions. But, what about using it in some informal occasions like everyday conversations? Would that be acceptable? and, since I'm not a native speaker, I want to ask: would such usage (in informal occasions of course) make me appear less "alien" to those native speakers? Or,is it that I better not use it in any case? Thanks for any advice.