阻止某人做某事在初中学的三种有Stop somebody from doing something,Keep somebody from doing something,prevent somebody from doing something,这里的keep是不能省略from的,省略了之后，是使某人一直做某事的意思，其他两个可以省略from。高中还会学到block somebody from doing something，discourage  somebody from doing something

stop sb from doing sth.

prevent sb from doing sth.

keep sb from doing sth.

其中前两种都可以省略介词frpm，第三种不可以。