I'm a native English speaker. On a site where I help Russians with English, one of them wrote the sentence:
My watch has been working good since I fixed it.
Naturally, I pointed out that the correct way to express this is with well or fine, however he insisted to the contrary, instructing me as follows, and I quote:
no, actually good has become an adverb long time ago, check some new dictionaries. Plus I was just told by a native speaker in the TeamSpeak that both variants (working good and working well) are valid, theres no mistake or how u put it "isnt grammatical" in using good. Its just a matter of choice or habit. Plus ofc the "feeling good", "I feel good I knew that I would" very old song n lots of things like that exist no matter what!
In all fairness, I wanted to consult other natives to hear their opinion on this. I'm very reluctant to believe that this is now considered correct (much less that it became an adverb "a long time ago.") I know that some natives speak this way, but that doesn't make it correct or acceptable in my book. What do you think?