"His dwelling has a red roof and a garage."
Translation:Locuința lui are acoperișul roșu și un garaj.
Why is the definite article used for acoperiș ? Can we say "un acoperiș" instead?
Well... this one is a though one to explain, but here it goes.
The definite/indefinite articles are used slightly different between languages.
When I hear "un acoperiș" I take into account that there might be others as well. "Casa are acoperișul roșu" = "The only roof of the house is red" "Casa are un acoperiș roșu" = "The house has a red roof, but there might be a blue one as well" - take into account though, that "The house has the red roof" means something else (the red roof that we bought together or something)
That being said, "un acoperiș" should be accepted, but "acoperișul" is more commonly used.
PS: I translated withe "un acoperiș" as well. The answer was for "Why is the definite article used for acoperiș ?"
It's "un acoperiș". "A roof" has indefinite article, and "un" is the romanian equivalent. Trust me, I'm Romanian.