Translation:What should I wear to go to this party?
I agree. Countless times in the past, I've pondered the question writers' mindsets: do they want 要 to mean want, will/going (future), or need. Should I use "should," because that's appropriate in English, or are they trying to be pedagogic with odd and awkward questions? It would be very helpful if they had a clear and consistent usage of such ambiguous terms across questions, or at least explanations for their logic in specific instances.
No two languages have a one to one correspondence between words. What are seeing here is that 要 usually corresponds to want/need/will in English. This question in Chinese is one I might ask a friend. Using want need or will in the English question doesn't work. Thus they are giving us the equivalent meaning in English. We will run into many more of these... Hopefully understanding this will also help us be more tolerant and encouraging to people who are learning each of our languages:-).
When you get a "wrong" answer that you think should be acceptable, don't forget to hit the little report button to let the developers know. These comments are helpful for us students to know we were on the right track, but the developers don't really look at them. If you want a developer to add a correct answer, you need to report it.
Is "What do I want to where to this party?" or "What do I need to wear for this party?" also an acceptable answer? I guess that would depend on the context. I thought the speaker was talking to themselves, instead of asking someone else.
Also, why does 要 mean 'should' in this sentence rather than it's usual meaning of 'want' or 'need'?
If you look up 要 in most any dictionary, you'll see that it has a bunch of meanings including "should". In this sentence, whether the speaker is asking someone else or themself, they're really asking "What's the best/ proper thing to wear". I think most English speakers would use "should" in this situation.
It appears Duolingo has introduced a set of cards rather than the free format in the web version since yesterday. Acceptable solutions should have been dramatically limited, but I failed this with a sentence "What clothes should I wear for the party?" I propose to drop the card of "clothes" here.