"Those people are young."
Translation:Ty osoby jsou mladé.
I'm confused. It has accepted my "Ti lidé jsou mladí" as correct and offered an alternative answer: "Ty osoby jsou mladé". But in a very similar case in another exercise it didn't accept "mladé osoby" and corrected it to "mladí lidé". :/
Osoby is more direct translation of "persons". Lidé is also possible, but strictly speaking it is "people". Perhaps we are a bit inconsistent and allow to mix them in some sentences and not in some other ones.
masculine animate nouns - ten pes (singular nominative) -> ti psi (plural nominative) [the dog-the dogs]
masculine inanimate nouns - ten strom (sg. nominative) -> ty stromy (plural nominative) [the tree-the trees]
feminine nouns - ta žena (sg. nominative) -> ty ženy (plural nominative) [the woman-the women]
neuter nouns - to město (sg. nominative) -> ta města (plural nominative) [the city- the cities]
ta osoba (feminine sg. nominative) -> ty osoby (feminine pl. nominative)
Below it is explained, that lidé is people and osoby is persons. But I typed as traslation "Ty lidé jsou mladé" and that was marked as wrong. The translation duolingo proposes actually means "Those persons are young"