"What a man you are!"
Translation:Quel homme tu es !
if "a man" = "un homme", shouldn't "what a man you are" = "que un homme tu es"? what happens to the "un" in the french translation?
Quel is used as it is the exclamative adjective. No indefinite article is needed :) http://french.about.com/od/grammar/a/adjectives_exclamative.htm
since there is a question word at the beginning of the sentence, there is no need to invert the noun and verb.