ok so i can't decide if Clover doesn't curse often or he curses a lot-
he either tries to avoid cursing at all costs, saying it's unnecessary and rude. and if you ever hear him curse it means he's genuinely angry and you should run for ur life :D
or he curses like a fkng sailor-
people always say that Clover would never curse, such an innocent soul would never say something like that :(( and then they hear him being slightly shocked saying something like: "oh fuck that scared the shit out of me" and people are like :O and the thing is that Clover is fully aware of what people think of him, so he even curses more on purpose to surprise them