"When is it cold in Korea?"
Translation:한국은 언제 춥습니까?
This makes sense to me but maybe it's just an English speaker's bias. We'd more naturally say 'When is it cold in Boston?' than 'When is Boston cold?'. But maybe Koreans think differently ... what is awkward in English could be preferred in Korean? Hopefully Duo has a lot of native Korean speakers priming the system with correct answers in the background. It would be helpful for Duo to display that data ... they tell us one alternative answer ... maybe an ordered list of answers with the most natural (to Koreans) on the top would help us speak more naturally?