"Quanti degli anni sono nostri?"
Let's break down the Italian a little: Quanti = how many, degli = of the, anni sono nostri = years are ours. It's an unusual sentence and you may intuitively think it is asking a more familiar question such as "How old are we?" but we need to be careful not to jump to conclusions. I would suggest "quanti anni abbiamo" for "how old are we" Hope this helps :)
Who cares if it would ever be used practically? The purpose is to learn how Italian sentences are formed, and since this helps you learn correct grammar, there's no problem with it. Duolingo's primary purpose isn't to teach you phrases you'll be likely to use in Italy, but to actually teach you the language, so that you can form your own sentences. Weird or not-likely-to-be-used sentences are great for this. They help you concentrate on the grammar and not the practical use of it.
There seems to be a depth limit, so my replies are unfortunately out of order. Anyway, I'm fairly confident that "How old are we?" is incorrect. The standard phrase is "Quanti anni hai?" so just as Chris123456 suggests, it should conjugate to "Quanti anni abbiamo?"
Instead, this sentence reads as if it were translated back and forth: "How old are we?" -> "Quanti anni abbiamo?" -> "How many years do we have?" -> "Quanti degli anni sono nostri?" I really wonder how it was created.
A huge part of learning a language is being familiar with common idioms. We should be learning idomatic phrases rather than nonsense ones. Instead, these nonsense phrases encourage us to ignore context.
Grammar is important, but it's just one ingredient in a language. Native speakers often use nonstandard grammar anyway.
I don't understand how you can defend these phrases. I work hard trying to understand the meaning of what I type, but sometimes it's just a waste of time here. :(
These forums are a brilliant idea. At least I can look at the discussion and confirm that a phrase is nonsense.
Maybe I have some weird definition of "nonsense" that's different from everyone else's, but I don't believe I've seen a single nonsensical sentence on here. There have been weird ones, but just because it isn't something you'd use every day (or even ever) doesn't make it not mean anything, right? To me, "How many years does he have?", even without knowing its idiomatic nature, is fairly easy to figure out, in my opinion.
Strictly speaking that would be correct, although not idiomatic English; and it is hard to conceive of a situation in which this sentence would be used. It would have to be very contrived and would apply, for example, if 'we' had been lent something on a temporary basis. And even then we would not use the present tense, but would employ the future, so that it would read: 'For how many years will they be ours?'