Translation:What were you all discussing just now?
I agree the translation is fine, but I personally would say "what were you just talking about." This Chinese course almost always requires you to put the time word at the end of the sentence, but there should be some flexibility. As the location of the time word can often vary. "what were you just talking about" may not be the best example as it is a little colloquial, but it should still be accepted I think.
I think Duo may be trying to be trying to emphasize the difference between 刚 “just” and 刚才 "just now." Given different contexts, 刚 "just" can indicate a minute ago, an hour ago, or even the day before. However, 刚才 "just now" indicates the immediately preceeding moment.
I don't think your sentence is colloquial as opposed to formal, but I agree that it's not the best example, because "just" itself can't be moved. It has to be "just now" if it's at the end (though "what were you just now talking about" is also a possibility, albeit a less natural one).
However, it's certainly true that in many other cases in this course more versions of sentences containing time words/phrases need to be added to Duo's database to account for the fact that many time words/phrases are movable in English.
I don't think the English translations need to be word-for-word. This is a course for learning Chinese, not a course for becoming a master translator. The purpose is to learn. Students shouldn't be penalized for using a natural sentence in English that gets the job done.
"You" is used in English to address both singular and plural audiences. Many languages have different words for singular and plural but English does not. Leaving out "guys" is just as correct (in fact, it's arguably better - "you guys" is more colloquial).
"What were you talking about just now?" is 100% correct whether "you" is one person or many.
What were you talking about just now?
It is not good language to put in "guys" !!! This is just not necessary!
It just seriously didn't let me put "you", but then accepted "y'all".
I think we can officially just close down Western civilisation and give up now.
"You guys"? Seriously? Why not then "you gals"? We are living in a PC world after all! :-)
"what were you guys talking about just now" was rejected but I think it should also be allowed
The "correct" solution, "What were you talking about just now?" looks strange. The verb is the preterit tense, while an adverbial phrase "just now" is used together. Posted on Nov. 19, 2017.