Grammar: Adverbial Clause（1）
语法：状语从句(1)

状语从句在句中作状语，可修饰主句中的动词、形容词和副词等，由从属连词引导，位置可放在句首或句末。放在句首时，后面常跟逗号；放在句末时，从句前往往不用逗号。根据含义，状语从句可分为时间、原因、让步、目的、结果、方式、条件、地点等。

1．时间状语从句: 由下列从属连词引导when (当……时), as (当，一边……一边), while (在……期间), as soon as (一……就), since (自从), till / until (直到), whenever (任何时候), after, before等。

When my cousin came yesterday, I was playing table tennis.
As he grew, he got more knowledge.
After the Chairman declared the Congress open, the National Anthem [ `AnW[m ] was played.
当主席宣布大会开始后，国歌奏起。
While the teacher explained the text, the students listened attentively and took notes.
Call me as soon as you arrive in Beijing.
Television has gradually controlled American's free time since it was invented at the end of 1930s.
The farmer had been harvesting the crops until it was completely dark.
She was a cashier (出纳员) before she came to university.
Whenever my uncle visits us, it will rain.

2．原因状语从句：由从属连词because (因为), since (既然), now that (既然), as（强调客观原因）等引导。

We work hard at English because it is the basic skill in foreign exchanges.
Since he is very busy, we had better leave him alone.
既然他很忙，我们最好别打搅他。
Now that you have recovered from your illness, you may start working now.
既然你病好了，你可以开始工作了。
As the weather was fine, we decided to climb the mountain.

3． 让步状语从句：由though / although (虽然)， as (尽管), even if / even though (即使), whatever / whoever / however / whenever / wherever, no matter what / who / whom/ how / when / where (无论什么/谁/如何/何时/何地)

Although she was very weak, she worked as hard as everyone else.
They suffered a lot even though they had made very good preparations.
他们遭受了严重的损失，虽然他们做了充分的准备。
Beautiful as she is, she is not very intelligent.
虽然她很漂亮，但她却不很聪明。
Fast as he runs, he didn't win the game last time.
Whatever you do, I will support you. (No matter what you do, I will support you.)
Whoever told you this secret will be punished. (No matter who told you this secret, he / she will be punished.)
Give this ticket to whoever comes first. (No matter who comes first, give this ticket to him / her.)
However hard I try, I can't pronounce that word properly. (No matter how hard I try, I can't pronounce that word properly.)
无论我怎么努力，都无法把这个字正确地发出来。
Whenever my sister's boyfriend comes to see her, she will be very delighted. (No matter when my sister's boyfriend comes to see her, she will be very delighted.)
I would like to go wherever I am needed. (No matter where I am needed, I will go there.)