"I am not a man."
What? I feel like this answer is weird. What about じゃない？how are there no comments on this yet?
I don't think there's anything weird about the answer at all. Also, are you sure it doesn't accept じゃない as an alternative?
Unless this happens to be a newly added sentence, I would almost certainly have used じゃない on it before. I would remember if this sentence kept rejecting my answer, unless I've somehow never encountered it yet.
All of the following (among others) should be acceptable:
やあらへん shouldn't be accepted unless all other dialectical forms are included, which would make the course extremely overloaded. Nevertheless, +1 for thoroughness.
Trying to subliminally sneak in some 関西弁. Guess I should have made it a bit less conspicuous by hiding it in the middle of the list. :P
This wasn't a written one but a choice selection one. Thank you for this feedback, though! Good moogle, have a kupo nut.
Here's a 'now' comment. This sentence is important in developing familiarity with polite forms. じゃない is the casual (colloquial) equivalent of ではありません.
ではありません is the polite negative form of です。This should be remembered as a set rather than trying to parse it (unless you want to delve further into the grammar aspect).
I didn't write私 even though I didn't necessarily need to? You could imply i was talking about myself without it, i think.