I was thinking, if I said “that worked out good” it sounds wrong/awkward, but if I say “that worked out well” it sounds right. I mean, good and well are almost synonymous, so why does one sound right in that phrase and one doesn’t?
“Good” is primarily an adjective, and “well” is primarily an adverb. They both indicate positivity in something, but that’s about all that makes them synonyms. They are different parts of speech that serve different purposes in a sentence.
You wouldn’t say, “That was a well book.” or “He’s fighting the well fight.” or “I am well to go.” If someone asks your opinion on a movie, you wouldn’t reply, “It was well.”
Same reason you shouldn’t use “good” where “well” should go, though in informal language, it has become fairly common.
When people ask me if I am going good, I reply, “I rarely do good, but I often do well.”
Or as the saying goes " Superman does good. You’re doing well"
From The Big Bang Theory:
Kripke: You gave it to her good, eh?
Sheldon: No, I gave it to her well.