Compared to working from a book it is ace - you get listening, speaking, reading and writing and it gets you where you want to be

I did the first three levels of Ukranian and when I went to Lvyv I picked out a couple of hundred words in shops and restau

Could I speak? No, but Duolingo gets you onto the pitch faster and better than anyone else - it gets you in play fast - so you can start learning the language properly