english is one of the most useful subjects in school, tell him that he will be able to learn so much amazing shit if he learns it, if u guys are at school, study STEM subjects - math, physics, chemistry, biology etc. and english obv. other shit u can "skip" generally speaking xD
not knowing english is an insane tax on your self development u gotta rely on other people to translate shit, it takes time and money, it's just not worth it at all, so u guys HAVE to know english it's in your best interest, even if your teacher is a dumb bitch, try to learn as much as u can. + u can easily practice it on the internet nowadays.