四、状语从句(Adverbial clause)
在复合句中，修饰主句的动词，形容词或副词等的从句叫做状语从句，状语从句根据它表达的意思可分为时间，原因，条件，比较，目的，结果和让步等类。
时间由as，after，as soon as，before，since，until，when，whenever，while等连词引导。
As he explored the sea,he took a lot of picture. As soon as he arrived in France ,he called me. He has been in Shanghai since he was born. Don't come in until you are called. Whenever we're in truble,he'll help us . While I was watching TV,the bell rang. 原因
由as，because，since，等连词引导
I didn't go surfing,because it was too cold. As the car is expensive ,we can't buy it . Since he was busy ,he didn't come. 条件
由if，unless等连词引导
If you travel in India,you can use English everywhere. I won't pass the exam unless I work hard. 比较
由as(so)??as，than等引导
Canoeing is not as(so) interesting as sailing (is). Li Lei swims better than Jim (does).
结果
由so??that，等引导
He was so weak that he couldn't walk on. 目的 由so ，so that等引导
We'll sit near the front so we can hear the speaker better. He sat in the dark so that he couldn't be seen. 让步 由although，even though等引导
Although the traffic was heavy ,we got to the railway station on time. Even though he is eighty,he looks strong and healthy. 1