Only by context. Similarly, we English speakers use "you" for both singular and plural while German has two separate words ("du" and "ihr"). For the most part, context makes it extremely clear whether you're talking about the person/people you're talking to ("Sie") or totally different people ("sie"). However, it's easy to imagine scenarios where this would still be a bit ambiguous, and for these, other cues like gestures, intonation, etc. can make it clear whom you're talking about.
Same question here ! Duo never told me how to form the past tense in German (I am currently in the "modal" lesson), and just gave me a sentence in the past tense for me to figure out that it has "ten" at the end. And just after that, he doesn't want the past tense for "wollten" !
What a nasty owl you make !
Pay attention to the small dots above the "o". "mohten" would be past tense, but "möchten" is the conditional form named Konjuktiv II.
Anyone else find the microphone activity bizarre? It seems random whether or not it accepts my attempt to speak the phrase. Occasionally, as what happened just now, I accidentally pressed the end recording button before I had said a word meaning it evaluated nothing, yet it passed me! Other times I swear I had nailed the sentence perfectly only to be given wrong each time.
Since "möchten" is subjunctive and so conjugates differently from other verbs, I'll use "gehen" in my examples:
For "you," "Sie" is capitalized, and verb ends in "-en": Wohin gehen Sie
For "she," "sie" is lowercase (unless at beginning of sentence), and verb ends in "-t": Wohin geht sie (this is where "möchten" is different: Wohin möchte sie)
For "they," "sie" is lowercase (unless at beginning), and verb ends in "-en": Wohin gehen sie
Note that, for "you" and "they" at the beginning of the sentence, the forms look exactly alike (Sie gehen can be "you go" or "they go"). The subject would then have to be inferred from context. (Duo will accept both translations.)
I entered 'whereto do you want to go', & although I was marked correct, it said that 'where_to do you want to go' is more correct.
Er ... don't use either. "Whereto" is super old-fashioned, and we never use it in modern English. As for "where to," we never phrase it that way either. Move "to" to the beginning ("To where do you want to go?"--still pretty awkward, though) or the end ("Where do you want to go to?"--better), or just leave it out altogether ("Where do you want to go?"--best).
Both translations are correct, so Duo accepts both so that you won't be marked wrong if you happen to think of the wrong one. I'm not sure why you would think that no context means there can only be one translation; in fact, usually the lack of context means Duo needs to accept multiple answers because there's no way to determine which answer is more correct.
In English, "Where do you like to go?" is a question you might ask someone about where they like to go every Saturday, or every summer.
"Wohin möchten Sie gehen?" is a question about where someone would like to go for a specific event, time etc. For instance, you are talking to your boss about where to go for lunch, you might say, "Wohin möchten Sie gehen."
Of course, I have never had a boss that I had to use the formal "Sie" with...