不定词.It's stupid of him to speak ill of others

问题描述:

不定词.It's stupid of him to speak ill of others
To speak ill of others is stupid of him.
It's stupid of him to speak ill of others.
He is stupid to speak ill of others.
这三句话的意思一样吗?

是一样的It's stupid of him to speak ill of others.和He is stupid to speak ill of others这两句话是可以同义转换的但是To speak ill of others is stupid of him这句话会造成句子的头重脚轻,所以用it作为形式主...