Translation:Is your mother's toothbrush white or green?
You will find it either "il mio/tuo/suo spazzolino" or "lo spazzolino"; never "il spazzolino".
i wrote "Your mother's toothbrush is white or green?" But they said it was wrong, because they wanted "Is your mother's toothbrush white or green?"
I think they are the same sentences, and mine should have been counted as correct. Is there some esoteric reason that mine is an incorrect translation?
In general, you can use a declarative sentence in English to form a question. But I'd argue that it doesn't really work for posing contrasting alternatives (white or green) and that you need an interrogative sentence here: "Is your mother's toothbrush white or green?" or "Your mother's toothbrush, is it white or green?". [Not a native speaker]