How do I know I have a skill/I did all lessons?
The (French) tree has the balls- The balls are skills which are divided into levels which are divided into lessons?
How many levels we have in the weather "ball" by example? Or any others? Always the same amount or different?
How do I know that I completed all levels in a skill? I get everything right, but then I have no idea should I continue. If it gets more complicated/or brings new words, then I should, but if not, then no need.