Is "For Free" Correct Grammar?
The Quick Answer
Strict grammarians will tell you that "for free" is grammatically incorrect because "free" is not a noun, and this means it cannot be preceded by "for" (a preposition).In their view, something is "sold for nothing" or is "sold free."
However, through common usage, "for free" has become acceptable.
Is the Term "For Free" Grammatically Acceptable?
Strict grammarians assert that the term "for free" is grammatically incorrect. According to them, the example below is wrong:- Music critics get their records for free so their opinions usually don't matter. (Marilyn Manson)
(1) "For free" is grammatically unsound.
A preposition must sit before something functioning as a noun (i.e., a noun, a pronoun, or noun phrase). As "free" is an adjective, it cannot be preceded by the preposition "for."
(2) "For free" is logically unsound.
Strict grammarians state that "for" is a shortened version of "in exchange for," and "free" is a shortened version of "free of charge." So, if both were expanded to their full versions, we would have "in exchange for free of charge," which is nonsensical.