"Los elefantes son grandes."
Translation:The elephants are big.
I know French a lot better than I know Spanish, and in French the article is often used when it wouldn't be in English.
In French I would say "the elephants are big" when talking about all elephants in a general way when in English I would leave out the article and just say "Elephants are big".
Obviously, I would also say use the article in French when talking about a specific set of elephants, and in English that would likewise require the article. Is it really not the same in Spanish? Some Duolingo Spanish sentences similar to this one accept the general response in English (without the article). I feel like this one should too. td;dr I think "Elephants are big" should be an accepted answer.