Suggestion for which words to practice
When you go to the page for a particular word there is an option to remove that word from your practice lessons in future. This is obviously useful if you've mastered the word and would rather spend your time practising words you are not sure about.
But its a painful process to go to each page for each word and click a button to remove it - I'm not even sure all users know about this feature because it's sort of hidden. Instead I suggest putting this option as a popup for each word when you're actually practising your lessons. That way you can immediately spot a word you know and remove it from further practice. There could just be a button that pops up with the definitions for each word to achieve this.
What do you think?
As clumsy as I could be, I would probably be accidentally removing words right and left. There would need to be an easy and highly visible "restore word" button or I would quickly have nothing left to practice LOL