Oh, the frustration...
I just got to the final question of a lesson: translate "a wedding" into Swedish. No hearts left, but I tell myself, "no problem; I know wedding." I can save my heart refill for later.
Confidently I type "ett bröllop" into the box, and I press enter in anticipation of the sweet celebration music and my 10xp. Bwwwwop, bwwwop, bwwwwoooooowwwub.... I look back horrified, and then I realise: translate "wedding".
If I had a desk, I would have flipped it.
Right click anywhere on the page, and click "view source". Search the page for "level_" and you will see a bunch of variables pertaining to your progress. It will show you how much experience you need for the next level, how much you have, the percentage of the level complete, etc.
Dirty, but it gets the job done if you really want to know this stuff.