Well look, it's simple (examples in French)

止める・止まる: stop > arreter/s'arreter,
動・・動かす: move > bouger/ se bouger
沸す・沸・: boil > faire bouilir/ boullir
始める・始まる: start > Commencer (there is only one for this one, but in English you have start, begin or commence, where start sounds more like 始まる)

Usually, Latin languages use the reflexive "se/si" and German "sich".
Sometimes theere is no reflexive so you have to say "make + verb" like in "make boil", so that you know it's doesn't boil by itself.