Translation:This room is not bright.
The time lag between あ か る is too short to be heard & differentiated for beginning learners
Akarui is the dictionary form. We turn i into ku, Akaruku, so we can add nai and make it negative....Akarukunai.
"This room is not light" is an accepted answer. In my American dialect at least, that would only refer to the "weight" of the room (however one would measure that) so wouldn't make sense here (or much of anywhere).
However, I wonder if this answer is getting at something not necessarily well expressed by "is not bright." What does it mean? This room isn't well lit? This room doesn't have any lights? The lights in this room are off?
Hmm "It is not bright in this room" was incorrect. Does that not mean the same thing more or less?
I'm wondering this as well. In English it is more natural to say "it is not bright in this room". "This room is not bright" sounds like the room itself should be glowing!
At what point does へやは明るくないです make "This room is not bright" as opposed to "This room is bright isn't it"? Would it just be the question mark at the end that allows me to determine which one it translates to?
"This room is bright, isn't it?" would be "(この)へやは明るいですね". (Unnegated bright + ね.) "Isn't this room bright?" would be "(この)へやは明るくないですか". (Negated bright + か.)
Glad I wasn't the only one who heard it that way. I think they spoke it so fast that the a elided into the next sound. Sure wish they had a turtle button like in French and Spanish!