In Belgium, you sit in a class have and X kind of courses. If you fail like 2-3 courses at the end of the year, you'll have to follow all those courses again in High School. Is this also possible in the Harry Potter movies? I could understand if you fail for 1 course, you'll have to redo that single course in Hogwarts.
I know they take exams and such, but is there anyone who wasn't allowed to go to the next stage / year? And had to redo his courses? I didn't really notice anyone in the movie franchise.