Peer tutors
Again, this is something that is portrayed frequently in American movies but does happen in real life too. The idea that someone from your own school year can tutor you in a subject seems pretty weird to the rest of the world. Sure, they might understand it slightly better than you, but they’re not a teacher.
Elsewhere, the culture is more to employ an adult, or a college student to come and tutor you, and pay for the service. These people tend to have teaching qualifications, and you know, actually know what they’re doing.