adjust question type frequency
For instance I find I get the best retention and understanding from translating spoken French into English, to a lesser extent written French into English and I get almost no retention when translating English into French, though I do find those questions help w/ grammar. I'd just like to get more of the questions that challenge and help me...
One of the problems I had at the beginning was that I could never remember the word "cangrejo". Practicing was not very useful on Duolingo, because I always seemed to be primed to the word by sentences from Spanish -> English that contained it.
I think I suggested it a long time ago, but I wish there was something like "Mastery Practice" wherein all sentences were randomly drawn from sections I had mastered, and were only of the kind you're describing: Target language audio -> English, Target language text (sentences) -> English.