My only issue with Duolingo (which I'm using to attempt to learn German) is that sometimes the translations (German to English) don't make sense in English --
Such as: Der Junge isst den Apfel (The boy eats the apple). In English, we'd probably say, the boy eats an apple. I understand this is the grammatically correct way to say it in German, but for someone starting out, it's frustrating. Same with conjugations. I'd rather get the right word down than worry about tense / gender, etc.
I feel like there needs to be two settings: One for individuals who want to learn the language, and one for those who want to learn enough to get by for travel / general conversation.
Also, Duolingo doesn't seem to cover the spoken language much