在 so.that 句型中,当主句和从句的主语一致,但主句是肯定式,从句是否定式时
可简化成 enough to do sth. 或 too.to do sth.结构
与enough to do sth.转换时,形容词或副词应变为与之相反的词,前面的动词为否定式
He is so young that he can’t go to school.=He is too young to go to school.
=He is not old enough to go to school.他还没到上学的年龄
如果主从句的主语不一致,须在 to do sth.前加 for sb 作为不定式的逻辑主语
The problem is so difficult that we can’t work it out.
=The problem is too difficult for us to work out
=The problem isn’t easy enough for us to work out.这道题太难了,我们解答不出来