hey, native Poles have a problem with this one - please, don't discourage learners ;P
"Man eating" or "Man is eating" are both incorrect and sound unnatural. Polish people don't use the article the same we English speakers do, and the point is that you have to get used to this.
I think, i don't know if I am right but, its pronunciation is Nężczyzna je not Mężczyzna je.
The letter N makes the "n" sound in polish and english. The letter M sounds makes the "m" sound in polish and english.