"The man is ugly."
Translation:La viro estas malbela.
Well, not really. If you say "la viro malbelas", then it's something he does. Like "La kato kaptas la muson" is something the cat does. The -as ending is the present tense verb. You could say "the man is (doing) ugly", but I don't think that is what you want to say here. "La viro estas malbela" = "The man is ugly" is like a characteristic of how the man is or how he looks - and he really is ugly... ;-) Ĉiu povas vidi ke la viro estas malbela, stulta, dika kaj riĉa. Li estas la ĉefo de Norda Koreio.
No, this is incorrect. As said above, "La viro malbelas" means "the man is ugly."
"The man is being ugly" is an English idiom which really means "the man is behaving in an ugly fashion," which means he is perhaps screaming and throwing things, or being mean to someone. In any case, if you know the idiom, the phrase "the man is being ugly" means a lot more than the literal translation of the words. So it isn't a good example here.
Try "la roza belas" instead: "the rose is being beautiful." It's pretty much equivalent to saying "The rose is beautiful," isn't it?
An even closer English translation would be "the rose beautifuls" except we don't do that in English.