Checkpoints / Shortcut tests
Why are there more skills after the final checkpoint exam (35) than before it (29)? In other languages, like German, there is one more checkpoint than in Spanish, and only 20 skills after the final checkpoint. The checkpoints in Spanish don't seem to be spaced very well if one can skip at most ~45% of the course.
Asegúrese de que usted practica ;) It is fine, but odd; asegúrese usted de practicar or usted asegúrese de practicar.