too...to... 与 enough...to... 与 so...that...的区别

1.too+adj./adv. to+v.太...而不能做某事
例：He is too young to go to school.
他年纪太小还不能上学。
2.adj./adv.+enough to +v.足够...而能做某事
例：He is old enough to go to school.
他足够大了能上学了/他已到了上学的年龄了。
3.so +adj./adv.+that从句 如此...以致
例：He is so old that he can go to school.
通常来说，这三种句型可用于同义句转换，具体如下：
too...to...
=not 反义词 enough to
=so...that 否定句
例：He is too young to go to school.
= He is not old enough to go to school.
= He is so young that he can't go to school.