Sure but my point was that Duolingo basing all of its courses on translating from one language to the other seriously limits its ability to actually teach you a language. My native language isn't English but as I'm writing these words I'm not translating, I think in English directly. If I switch to "translating" mode I'm a lot slower and I end up with unidiomatic English.
Any decent language learning course should try to immerse you in the target language as soon as possible, forcing you to actually think in the language instead of your own. There are many ways to do this, for instance making you answer questions. Instead of telling you "translate 'the cat is black' in French" they'd show you a picture of a black cat and ask you "Quelle est la couleur du chat?" and you'd have to answer "Le chat est noir". No English involved, like in real life. The problem of course is that such an approach is hard to correct by a dumb algorithm, especially as the concepts being taught become harder.
Any decent language learning course should try to immerse you in the target language as soon as possible, forcing you to actually think in the language instead of your own. There are many ways to do this, for instance making you answer questions. Instead of telling you "translate 'the cat is black' in French" they'd show you a picture of a black cat and ask you "Quelle est la couleur du chat?" and you'd have to answer "Le chat est noir". No English involved, like in real life. The problem of course is that such an approach is hard to correct by a dumb algorithm, especially as the concepts being taught become harder.