be afraid to do与be afraid of doing有什么区别

1．be afraid to do 主要指按照经验或常识不敢去做某事或没有勇气去做某事.如：
The little boy was afraid to go out at night．这个小男孩晚上不敢出去.
注：在现代英语中,也可以用be afraid of doing 结构来表示上述意思.如：
He was afraid to tell[of telling]his wife．他不敢告诉他妻子.
2．be afraid of doing 主要表示担心会发生某事（是一种无意行为）,此时不能用be afraid to do 结构.如：
I was afraid of hurting his feelings．我怕伤了他的感情.
请再体会下列句子：
The girl was afraid to speak English before so many people because she was afraid of making mistakes．这个女孩不敢在那么多人面前说英语,因为她怕出错.
She was afraid to swim because she was afraid of drowning．
她不敢游泳,因为她担心会被淹死