With names of countries and companies, you can optionally indicate the people that belong to it with the wa- agreement, or the country/company itself just with i- (or whatever it goes with).
I know this doesn't really happen much in American English, but it's kind of like a lot of other dialects of English (including mine), where we'd say "The staff are very friendly" (talking about the individual people) or "The staff has doubled in size since last year" (talking about the staff as a collective). ("The staff have doubled in size" would mean everyone has gotten fat or something.)
Not just a dialect - it's now considered correct English to refer to a group in the way you describe, when you want to emphasize the members of the group (e.g."The staff are very friendly").
However, in English I could never say "USA play soccer". It's a hopelessly literal and unnatural translation. I would say "Soccer is played in USA" (passive construction) or "Americans play soccer" (people from USA, not the country itself), but then I would be accused of not understanding the grammar of the Swahili sentence.
Thanks norynkei! Good to have confirmation that the Swahili is correctly formulated. Then it is just the English that should be corrected because the literal translation is unnatural. I suggest "Americans" instead of "USA".
But maybe a closer translation would be "In the USA they play soccer".
Wait, you can say "Soccer is played in USA"?!?!? And you're a native English speaker? Sorry, simply asking because that is entirely impermissible in my dialect (to wit, American), and I'm just flabbergasted.
Yes, piguy3, I am a native speaker of British English and I think we just have to accept that there are differences between American and British English. (What you call "soccer", we call "football" and what you call "football we call "American football". Lots to get flabbergasted about there, too.)
After confirmation from norynkei that this Swahili sentence is referring to American people, not the USA itself, I suggested "Americans play soccer" instead of the given answer "USA play soccer" (which sounds very strange to my ear). Does "Americans" sound wrong to you in this context?
Yes, certainly "Americans play soccer" is totally normal.
I'll just have to be updating how I reply to all those threads in English from Spanish where I've said the definite article is required before "U.S." in English (in Spanish it's very common to omit it, and I had thought this is a hard-and-fast difference between the languages, but, well, live and learn).
Actually "staff" is an instance where variable verb agreement is common in American English, so I guess it's a good example from the angle of widespread comprehensibility.
Here you didn't seem to think much of translating this as "Americans," but how else might one render "the people that belong to" the U.S.? As far as I understand "The U.S. are..." is used in reference to e.g. the national soccer/hockey/water polo/etc team but not so much the general American people.
Piguy3, I confess I am not sure what you are referring to. I didn't actually make any comment in the post you mention (https://forum.duolingo.com/comment/24235756). That was AttilaVarg127747, who suggested "Americans play soccer", as I have done here.
Maybe Attila, like me, is thinking about ordinary people kicking a ball around for fun, rather than the USA having a national team. And maybe the Swahili sentence here could be interpreted either way.