1、含義上的區別

too...to...中文含義是太...而不能做某事。

例：The boy is too young to go to school.

enough...to...中文含義是足夠...而能做某事。

例：I have enough time to finish the job.

so...that...是如此...以致於...。

例：He always is so busy that it is very late when he arrive home everyday.

2、用法上的區別

too...to...和so...that...：too和so接形容詞或副詞需後置，即形容或副詞在too和so的後面。如：HE is too fat to...；HE is so tall that...。

enough...to...：enough接形容詞或副詞需前置，即形容詞或副詞需在enough的前面，如he is strong enough...。

so...that... 的that後面跟的是從句充當句子成分：too...to...和enough...to...的to構成動詞不定式充當句子成分。