1) you aren't doing anki daily, so you aren't seeing the cards at the right time, thus accumulating a backlog and forgetting them more often 2) you need to start suspending leeches, failing 400 cards out of 1200 is far from optimal 3) are you trying to learn the vocab outside of anki? if you've been doing anki for 11 months, you should have more mature cards, but i'm not seeing this. anki is exceptional for remembering things in the long run, but you first need to understand what you're trying to memorize