"Are you a man?"
Translation:Czy jesteś mężczyzną?
"Jesteś człowiekiem?" Is also accepted, but I would like to know when you would ask one and not the other.
Każdy mężczyna jest człowiekiem, ale nie każdy człowiek jest mężczyzną. (Each man is a human but not each human is a man).
"Człowiekiem" would mean man as in a member of the human race. So "Jesteś człowiekiem?" might be like in a fairy tale or a myth with centaurs, mermaids, or talking animals. A creature meeting a human for the first time might ask "Are you a man?", even if they are talking to a woman, a boy, or a girl.
Well, mostly because the basic form of the word is "mężczyzna", not "mężczyznak" ;)
"mężczyzna" is a masculine word that ends with -a and undergoes declension as if it was feminine.
Czy jesteście mężczyzną? - Are you all a man?
Doesn't sound quite right. It should be:
Czy jesteście mężczyznami? - Are you all men?
But that's not accepted here, since "man" is singular in the original sentence.