Translation:It is not good.
This is a rare example of an irregular conjugation, where いい and よくない have no visible similarity, they just have to be memorized.
よくないです means "It is not good." Adding は to get よくはないです means "It is not necessarily good."
I mean, I getya, but how are we supposed to tell the difference? How do I know this doesn't mean 'Not often' ?
I think good is "yoi" and to make it negative you have to take off the 'I' and replace it with 'kunai'. We know it does not mean 'often' because there is a 'nai' after.
Furthermore "often" is not an adjective so you wouldn't use "kunai" after it- plus that would make it "yokukunai".
That's almost right. "Kunai" is only for i-adjectives. It's "janai" in all other cases (that I can think of). So I reckon it would be "yokujanai" if it was anything.
if you replace the い with く but without the ない, it becomes an adverb. よく is an adverb.
よくない is "not good". よくないです means "it is not good". That's the difference.
"not good" isn't a real English sentence, and since this course is for English speakers, accepting slang isn't helpful
Not really. よく means often you can't conjugate it (in this case with ない). Also to say something doesn't happen very often it's better to use あまり :) e.g. あまり行きません I don't go very often
Report it. If "can I get..." is an acceptable translation of をください, then "ain't" should be a valid translation of ない/ません.
In this case, because of the lack of context, there is no should be no distinction between "It is not good" and "This is not good" -- both are acceptable translations for this sentence.
Can this not also mean "I am not well"? Is there any reason why that doesn't work?
That would be 元気(げんき)じゃない。The well/often that is よく (not quite the same as よくない, which is just the negative form of いい) does not mean well in the sense of one's health, to my knowledge. よくない just means "not good", without having anything to do with wellness, far as I know.
"Not good" and "bad" overlap but aren't exaxtly the same. It could be not good but mediocore