Collective nouns - British versus American English
Duolingo, please change your review of sentences including collective nouns to take into account British English.
Extract from Wikipedia (sorry it's not a better source, but sure it's the same everywhere):
In British English (BrE), collective nouns can take either singular (formal agreement) or plural (notional agreement) verb forms, according to whether the emphasis is on the body as a whole or on the individual members respectively; compare a committee was appointed with the committee were unable to agree. The term the Government always takes a plural verb in British civil service convention, perhaps to emphasise the principle of cabinet collective responsibility. Compare also the following lines of Elvis Costello's song "Oliver's Army": Oliver's Army is here to stay / Oliver's Army are on their way . Some of these nouns, for example staff, actually combine with plural verbs most of the time.
In American English (AmE), collective nouns are almost always singular in construction: the committee was unable to agree. However, when a speaker wishes to emphasize that the individuals are acting separately, a plural pronoun may be employed with a singular or plural verb: the team takes their seats, rather than the team takes its seats. However, such a sentence would most likely be recast as the team members take their seats. Despite exceptions such as usage in The New York Times, the names of sports teams are usually treated as plurals even if the form of the name is singular.
and probably never will ....I have just resigned myself to trying to remember what they want and getting frustrated when I forget ... but it is free and from an American company, I keep telling myself that I should just be grateful but sometimes, it is hard not to get a trifle miffed.