从句部分是用以补充说明主句中谓语动词发生的目的的。
表示目的状语的从句可以由that, so that, in order that, lest, for fear that, in case等词引导；
目的状语从句的谓语常含有may, might, can, could, should, would等情态动词。
例如：
You must speak louder so that /in order that you can be heard by all.
He wrote the name down for fear that(lest) he should forget it.
Better take more clothes in case the weather is cold.
引导目的状语从句常用的连词有： that（以便），so that（以便）， in order that（为了；以便），Lest（免得；唯恐）， for fear that（生怕；以免）。
用法
1) so … that…/ such ….that
该句式中重要考查的是so和such的区别。应注意以下可能出现的结构：
so nice a boy that…
such a nice boy that…
so beautiful/diligent/carefully … that…
such (fine weather/great improvement) that…
2) so that
Everyone lend a hand, so that the sowing was done in time.
该句式中主要考查so that 与其它短语的区别，如：
I took no notice of him, ___ he flew into a rage.
A.for that B.so that C.in that D.but that
由于so that也可以引导目的状语从句，同学们应特别注意从句中时态的运用。
3) so much so that
该结构用于形容词或副词之后，表示"到如此程度以致于"。如：
He was very weak, so much so that he could not walk.
I long to visit Beijing, so much so that I dream about it every night.
4) 注意结构状语从句与too….to..enough to…, so… as to结构的不同。
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