For better or worse in proper standard modern English, "you" is the sole 2nd person pronoun word if you are addressing somebody OR a group of people, no matter how many or who they are. "You" is singular, plural; formal, informal.
I think it is a good thing that English is one of the few major languages to go egalitarian, forget "formal/informal" rubbish, even if it may be fun to imagine "thou" making a comeback.
Unfortunately along with "thou", we also lost the plural "ye". While archaic, "ye" is still the only proper English 2nd person PLURAL of "you".
Different regions have come up with colloquial forms to try to fill the gap, as mentioned most prominently "y'all" in the Southern USA, "yinz" in Pittsburgh/Western PA area, USA, the more generally ubiquitous American "you guys" (or Jersey Shore variant "youz guyz" :P), or the more folksy "you folks".... but none are acceptable in proper written or spoken address.
"You all" is the closest to a proper modern English 2nd person plural, in foreign language classes in high school & college that's how I was told to translate a 2nd person plural pronoun so they know that I know the foreign language pronoun is plural, but it's also just a makeshift solution, and is imprecise. An English teacher calling out a group of 5 unruly students in the back of his classroom disturbing the class is addressing more than one "you", but he is not addressing "all" the students sitting in the class before him (also technically a problem with "y'all" but that's colloquial & casual anyway so it doesn't matter & an English teacher shouldn't be using it in class.)
So we are stuck with "you" as translation, whether it's "tú", "usted" or "ustedes".
Though if Duolingo wanted to help Anglophones distinguish between singular/plural & formal/informal 2nd person when translating into English, in order to better help distinguish the Spanish words, they could always allow the option of using "you" for "tú", but "thou" for "usted" and "ye" for "ustedes". :P
Exactly. I don't think a lot of people understand what Thou was. For many people, thou is only a word we hear in Church, and I remember that I was a little jarred by hearing du in Church for addressing God when I lived in Germany (du being the German equivalent to Tú)
none are acceptable in proper ... spoken address
Unless the English teacher is a "progressive educator" who realizes what a great word y'all is and is promoting it's use worldwide in all English speaking countries.
It is not correct to say *y'all is not correct in spoken address".
I live in Texas (the only state that was once it's own country.) We are a large voice for the use of this great word (y'all) and prefer it to all other ambiguous expressions that never properly express you plural
Join the movement. Learn to use this great word. You'll find it trickles from your tongue like Spring rains on Texas wildflowers.
Inqvisitor1 Also, you really like belabouring a point
Get a grip on yourself. Holy mackerel
It would be an error for Duo not to accept they as an answer, but to say it is a better translation is wrong. Actually it is important for Duo to keep reminding people that Ustedes forms exist. It seems somewhat easier to get our heads around Tú and usted than ustedes. If Duo just continually reinforces that van a infinitive is they are going to and don't reinforce the you plural form, y'all are going to miss the correct meaning of many things in real spoken Spanish. I used y'all because it does seem that Southerners have a distinct advantage because they at least have the linguistic concept which doesn't exist in standard English.
Y'all is definitely colloquial and not used extensively throughout the English speaking world, just in the Southern United States. The only advantage it has is that the people who use it do use it consistently for the plural you. You all is not uncommon, but certainly most people don't say it most of the time when addressing multiple yous. They simply say you.
If they didn't accept they in translation, always report it. But Duo does regularly show a specific or implied ustedes as the subject. That is probably because, although most English speakers are constantly struggling with Tú and usted, they forget about ustedes, the plural you, since we don't have one. Of course if this course were teaching Spanish from Spanish, Vosotros forms would also be regularly drilled. But they are unique to the form, so are not easily confused for third person constructions.
Lo van a comprender couldn't be he. It would be either plural you, ustedes, or either they ellos or ellas. They conjugation gives the possibilities, but the context would give the clues to which meaning. Duo often has insufficient context clues to tell, so both they and you are accepted