I don't know here, but in German, for example, you don't say "I am A man", because "a" means literally "one", and you cannot be "two" men at a time. And saying "the" is not correct either, if you are just talking in general. So you should not say an article in the cases with general descriptions and professions. But that is just my attempt to make sense of it, I might be wrong!!
Actually you do say "I am A man" in German. It's the same as in English, you don't say "I am one man"
I am not a man would be ''eu nu sunt un barbat'' but at the same time if you were to translate the sentence word for word in English it wouldn't make sense to say ''I am man''. I hope this makes sense
If this sentence was literally translated - word for word - would it be: "I not am man"? It's just interesting to learn the sentence structure.
Bărbat makes me think of "bearded", from barba. Man and bearded, hmm... I can see the logic, but is the etymology correct?
YES ! This is funny, because long ago you were not considered a man if you didn't have a beard :)