"How much butter do you want?"
Translation:¿Cuánta mantequilla quieres?
Why was my answer "¿Cuánta mantequilla quiere usted?" rejected, while DL insisted on "quieres"?
That should be accepted. I assume you reported it to Duo not just to us here?
This is because it was not asking for the pronoun use and it will be odd saying it like that in spanish.
I disagree. "Usted" merely clarifies whether "quiere" means "he wants", "she wants", "it wants", or "you want". Thus, it's necessary to form the "formal you". There is no indication that the sentence only accepts the "familiar you", so DGamser's answer should've been accepted. My answer was "¿Cuánta mantequilla quieréis?, which was also incorrectly marked wrong, and DIDN'T involve a pronoun. As for DGamser's sentence sounding odd, that's EXACTLY how I was taught to say it back in junior high/ high school Spanish class 84'-88'. If you're a native Spanish speaker, I'll defer to your expertise. Otherwise, I respectfully believe you're wrong.
Nice one Foofie. Bravely pushing the envelope there! (For those who don't know: quieréis - 2nd person informal, plural, used in Spain not Latin America I believe) Or foolhardy, I cant' decide!
Foofie, I think your answer should have been marked wrong, unless you're showing us a typo here. The correct spelling is queréis. There's no stem-change in the nosotros and vosotros forms of querer, so quer + éis. Try that next time and see if they accept it.
You could say ¿Cuánta mantequilla quieres tú? but the pronoun is usually ommited in informal talk. It's grammatically correct but doesn't sound natural.
It's not wrong because you used the pronoun (that's acceptable) but because in questions, the subject is placed after the verb, not before. Kinda like the way we change the word order in English questions as well: "The paper is black" becomes "Is the paper black?"