Hi. Veteran of spaced repetition here. The problem with giving you new cards when you've got 1000 to review is that your review number is going to go up up up and keep increasing, and you are not learning if your review stack is going up like that. Spaced repetition flat out doesn't work if you let reviews pile up like that. The reviews appear at optimal times for you to review them, and if you let them pile up, then you aren't reviewing them at the right time and will forget them or find recalling the meanings very, very difficult. This is why you /must/ stay up to date with your reviews. This is true of any studying, but spaced repetition makes it obvious /why/. I noticed today that a change was rolled out that sets a goal of 80% correct reviews as a "milestone" to achieve each day (along with 100 reviews and . Try to shoot for 70–80% correct in your reviews. In my experience, this is the ideal range of correct reviews to shoot for. If you're getting less than 70% correct this suggests you're trying to learn new words too fast and aren't fully learning the ones you've already seen, and if you're getting more than 80% right, you could probably increase the number of new words you learn per day (that is to say, you could do more cards in general). I suggest you sit down and knock out those 1000 cards and do nothing else. The next day, it should be fewer than 1000. The next day, even fewer than that. And so on and so forth until you finally get your count back under control. Because right now, with 1000 cards stacked up, you're not learning effectively, and the method Lingvist uses isn't going to produce good results. You /have/ to keep up with your reviews and study only a reasonable amount every day.