be afraid of 和be afraid to的区别其实非常好记,告诉你：
be afraid of doing/sth.意为害怕,恐怕,担心
be afraid to do sth.意为不敢做……事
给你句句子,你马上就能搞清：
he is afraid of being beaten by his father.他怕被他爸抽
这里明显用be afraid of,如用be afraid to的话,解释为“他不敢被他爸抽”,这太可笑了
he is afraid to touch the snake.他不敢碰那条蛇