Some prepositions in English would be really hard to learn as a second language. For example you would say "He is IN a movie." and "He is ON a tv show." I guess people would understand you if you said "He is ON a movie", but it just sounds a little off, amirite?

Yet, "He's in a tv show," doesn't sound so bad, until you repeat it over a few times.

You're on a bus, on the train, on a plane, in the car

Many languages delegate many meanings to the few prepositions they have, like how French (and maybe other Romantic languages) uses "de" to mean "of" and "from" and for possessive forms also.