It's more a matter of dialect.
Originally Posted by 2006
Don't say nothing.
=> Don't say anything.
Don't say nothing. (That is,) say something.
if there is very heavy stress on "don't" or a specific plaintive
stress on "nothing," then it would be a grammatically correct way of emphasizing that the speaker would rather have "something" than "nothing" at all.
In some languages (or varieties of a language,) negative forms are consistently used throughout the sentence to express a single negation. In other languages, a double negative is used to negate a negation, and therefore, it resolves to a positive. In the former case, triple and quadruple negation can also be seen, which leads to the terms multiple negation
or negative concord
Negative concord, popularly called "double negation", as in I didn't go nowhere
; if the sentence is negative, all negatable forms are negated. This contrasts with Standard English, where a double negative is considered a positive (although this wasn't always so; see double negative
). There is also "triple" or "multiple negation", as in the phrase I don't know nothing about no one no more
, which would be "I don't know anything about anybody anymore" in Standard English.