一． 副词（adv）
1、
修饰形容词或副词
⑴.Don't be so angry．
2、
替代词：与动词、形容词等连用，避免重复。
这样的动词有hope、believe、imagine、suppose、guess、think、be afraid等。
3、
的确如此，表同意。常用结构为：SO+同一主语+助动词/系动词/情态动词
⑴——They won the championship 5years ago．
——So they did．
4、
也 1）、表上文提到的一种情况也适应于另外一个人。常用结构为：SO +助动词/系动词/情态动词+另外一个主语
⑴——Mary can speak English
——So can I．
2）、表上文提到的两种或两种以上的情况也适应于另外一个人。常用结构为：So it is was with sb.。
5、
为了…… 表目的。常用结构为：SO AS TO DO STH和SO THAT—CLAUSE（SO THAT 既可以接目的状语从句又可以接结果状语从句。在目的状语从句中，常常与can、could、may、might等情态动词连用。在结果状语从句中往往不用情态动词，且要用逗号将其与主句隔开。）
⑴.He puts on glasses so as to see clearer．
6、
SO…AS TO DO STH。如此……以至于……（表结果）
⑴.He was so angry as to be unable to speak．
⑵．They started so early as to arrive in time．
7、
SO…THAT引导结果状语从句，有以下几种情况：
SO+ADJ/ADV+THAT—CLAUSE
SO+ADJ+A/AN+N+THAT—CLAUSE
SO MUCH/LITTLE+|U|+THAT—CLAUSE（|U|代表不可数名词）
SO MANY/FEW+PL+THAT—CLAUSE（PL代表可数名词的复数）
⑴.He is so young that he can't go to school．
⑵．He is so tall a man that he can almost reach the ceiling.
注意：①.在SO MUCH/LITTLE+|U|+THAT—CLAUSE结构中，LITTLE表示的意义为“多少”；若LITTLE表示“小的”意义，则必须用SUCH换掉SO。
Do you believe such little animals eat so little food a day？
你相信这么小的动物一天吃这么少的食物吗？
②.当SO 位于句首时，句中谓语动词经常采用倒装结构。
So fresh is the air at the top of Mount Tai that we can't help taking deep breaths．
8、
（NOT）SO …AS—CLAUSE 表不如……
⑴.John is not so polite as Bob．
⑵．He is not so good a player as his wife．
9、
这样；那样；就这样
⑴.Stand with your arms out，so．
两臂伸开站着，就这样。
⑵．So I called on you and asked if I could borrow some jewelers．
二．连词（CONJ.）
1.表结果：
⑴. The shops here closed so I didn’t get any milk.
⑵. The manager was ill so I went in his place.
2.表目的：
⑴. I gave you a map so you wouldn’t get lost.
⑵. She whispered to me so no one else would hear.
