"Whose jacket is this?"
It doesn't seem to accept the 「このうわぎはだれのですか？」. That is, it doesn't seem to like 「だれの」 at the end there.
I've been presented with this question quite a few times, and even after revising several times, I always enter:
Could someone explain why this is not an acceptable/unnatural answer? Thanks!
Because you wrote これ instead of この. But even if you'd used この, there's still a chance the contributors might not have added it as an accepted translation for this sentence yet anyway. ^^;
Testmoogle is correct. If the word 'this' is attached to a noun or pronoun it would be この. As a standalone it would be 'これ'. It is an important grammatical distinction.
これ = このうわぎ
このりんごはおおきいです This apple is big.
これはおおきいです This is big (apple being assumed)