Melina Enjuto wrote:
I have noticed the phrase 'for free' is used quite often in this website.
Please notice this is WRONG. It is incorrect usage which, unfortunately, has spread widely.
'Free' derives from the expression 'free of charge'. You wouldn't say 'FOR free of charge'. Correct usage would be, for example: 'I got this watch free' (or 'free of charge' or 'for nothing').
Melina: There is no "wrong" usage from a linguistics perpective (a) unless you are a prescriptivist or (b) unless you are speaking of usage by a non-native speaker. Native speakers can pretty much say whatever they want unless their English teacher is listening. :>)
Languages are in a constant state of flux. The fact that the use of "for free" has spread widely, as you observe, is an indication that it may eventually become standard usage. Those who use the expression "for free" are not thinking about the etymology of the word "free". Although "free of charge" clearly still in use in some registers, such as in advertising, it is being replaced in by "free" in the colloquial register and may well eventually be replaced by "for free".
That is not to say that expressions like "for free" are not annoying while they're still moving from Point A to Point B (i.e., acceptance as the norm).