史上最全状语从句知识点总结，建议收藏！状语从句在句中相当于副词，做状语，又叫副词性从句。
状语从句分为九类，包括时间状语从句、条件状语从句、地点状语从句、原因状语从句、目的状语从句、让步状语从句、结果状语从句、方式状语从句和比较状语从句。
1. 时间状语从句
⑴当......的时候：when，as，while
I fell asleep when/as/while he was doing his exercises .
他正作练习时我睡着了。
When he arrived in Shanghai ，his mother met him at the station .
他到上海时，他妈妈到车站接他。
While John was watching TV，his wife was cooking.
当约翰看电视的时候，他的妈妈在做饭。
She always sings as she walks .
她总是一边走一边唱。
注意：when 引导的时间状语从句中的谓语动词可以是持续的也可以是瞬时的；while和as 引导的时间状语从句中的谓语动词必须是持续的。
⑵一......就......：as soon as，the minute，the moment，the instant，immediately ，directly，instantly，no sooner … than...，hardly …when...，scarcely…when...
The children ran away from the orchard(果园) the moment they saw the guard.
孩子们一看到守卫就从果园跑掉了。
No sooner had I arrived home than it began to rain.
我一到家天就开始下雨。
⑶直到...... till，until，not...until...（直到......才......，not翻译成“才”）
I didn’t realize how special my mother was until I became an adult.
直到我长大成人，我才意识到我的妈妈是多么特别。
⑷ ......次......的时候：every/each/the last/next/any/the first...time
Every time I listen to your advice，I get into trouble.
每次我听到你的声音，我就会有麻烦。
⑸ once 一旦......就......
Once you begin，you must go on.
你一开了头，就应该继续下去.
⑹ before 在......以前
It was not long before he told me about this affair .
不久，他就告诉我这件事。
⑺ after 在......以后
After he had finished the work ，he went home .
他干完活，回家了。
⑻ since 自从......以来
We have been friends (ever since) since we met at school.
自从我们在学校相遇以来，我们一直都是朋友。
2. 地点状语从句
where，wherever
Generally，air will be heavily polluted where there are factories.
一般来讲，在有工厂的地方，空气会受到严重污染。
3. 原因状语从句
⑴ because（因为，与why配套使用）
⑵ since/now that（既然，因为）
Now that everybody has come，let’s begin our conference.
既然大家都来了，让我们开始会议吧。
⑶ as（由于）
⑷ in that（因为）
The higher income tax is harmful in that it may discourage people from trying to earn more. 更高的所得税是有害的，因为那会阻止人们努力赚更多钱。
⑸ seeing that/considering that/given that（考虑到）
Considering that he is no more than 12 years old，his height of 1.80 m is quite remarkable. 考虑到他仅仅十二岁，他一米八的身高就很引人注意了。
4. 目的状语从句
so that(以便)，in order that（为了），in case（以防），in the hope that（希望能......），for the purpose that（目的是......）
The boss asked the secretary to hurry up with the letters so that he could sign them.
老板让秘书快点处理信件，以便他能够签字。
The teacher raised his voice on purpose that the students in the back could hear more clearly.
老师提高声音，目的是后面的同学能够听得更清楚。
5. 结果状语从句
so … that...，such … that...，so that(以至于......)
It’s such a good chance that we must not miss it.= It’s sogood a chance that we must not miss it.
这是如此好的一个机会，以至于我们不能错过。
注意：so+形容词/副词，因为so是副词；such+名词，因为such是形容词。
6. 条件状语从句
⑴ if，only if，unless（除非，=if...not...）
We’ll start our project if the president agrees.
如果校长同意，我们将开始我们的项目。
⑵ as/so long as（只要）
You will certainly succeed so long as you keep on trying.
只要你坚持努力，你一定会成功。
⑶ providing/provided that/suppose that（假如）
Provided that there is no opposition，we shall hold the meeting here.
假如都不反对，我们就在这里召开会议。
⑷ in case that（万一，如果）
⑸ on condition that （如果）
7. 让步状语从句
⑴ though/although/as（虽然，尽管）
Much as I respect him，I can’t agree to his proposal.
尽管我很尊敬他，我却不同意他的建议.
注意：as 引导的让步状语从句必须用形式倒装，though引导的让步状语从句可以形式倒装
