C'est becomes ce sont when followed by a plural noun
There is nothing so egregious about one Duolingo exercise that would justify being deeply bitter. It might be good to just explore dictionaries and resources for why it was handled that way. BTW, "the final years" is accepted. I have spent the past 18 months working on making the English translations more natural and realistic but it is a never-ending task. Incidentally, while I occasionally find Reverso to be insightful, there is also quite a lot of incorrect information there, so caveat emptor.
I noticed some great changes that reflect "relaxed" translations that match the realities of our daily lives and not the strict "by the book" ones that make no sense. A lot more to do -I am sure- but it is good to see that a great deal of progress has been made.
Merci beaucoup !
I think it DOES mean 'final years' in some contexts. For example - les dernières années de la Deuxième Guerre Mondiale.
Don't be impressed. I cut and pasted that straight from Context Reverso. They gave me over 30 examples to choose from. If you haven't played with that site yet, go for it :)
If you're talking about meaning, no, there is none. But, where you are counting or numering, you must use one or the other. You can't say "Derniers ans" but must say "Première année / Dernière année". You can perfectly say "un an, deux ans, trois ans" et "une année, deux années,..."
There is only one English translation, but in French you use them in different situations. Maybe this article will help you as much as it did me ;) http://french.about.com/od/vocabulary/a/an-annee-jour-journee-matin-matinee-soir-soiree.htm
Dernière means last as in "past" or "previous". Like last year, last night, or last week. Last in that context does not mean final as in "the last one and there will be no more after".
It's not like saying "it's my last year in college" for example. You wouldn't say "c'est ma dernière année" in that case.