"Is it an owl?"
Translation:Er det en ugle?
Why does it not matter: "Er det en ugle" or "Er den en ugle"? Shouldn't we choose det/den according to the kind of the noun - in this case, an "n-word" en ugle would require "den", wouldn't it?
"Det" is used "as the subject of være/blive when the verb is followed by a noun, a pronoun or an adjective, irrespective of gender or number."
It actually works the same way in German with the neuter "das".