Ⅰ. so that 可引导目的状语从句和结果状语从句，引导目的状语从句时，句中常有情态动词can, could 等。如：
① They climbed higher so that they might see farther. 他们爬得更高，以便看得更远。
② I got up early this mornign so that I caught the first bus. 今天早晨我起得很早，结果赶上了头班车。
Ⅱ. so …that “如此……以致……”，so 是副词，在其后可跟形容词或副词，再跟that引导结果状语从句。如：
① He spoke so fast that no one could understand him. 他说得太快，没人能听得懂。
② The T-shirt cost so little that she bought several. 那件T恤衫很便宜，她买了好几件。
Ⅲ. such … that 与so … that 同意。但such 后跟名词或名词短语。如：
① She is such a girl that everyone likes her. 她是个人人喜欢的女孩。
② He made such raped progress that before long he began to write articles in English for an American newspaper. 他进步如此之快，以至于不久就开始用英语给一家美国报纸撰稿了。
：如果名词前为many 修饰时，用so 而不用such.