知识点总结
地点状语从句
通常由where, wherever 引导。
There are plenty of trees where I live.
Wherever I am I will be thinking of you.
方式状语从句
通常由as, (just) as…so…, as if, as though引导。
1）(just) as…so…
Always do to the others as you would be done by.
As water is to fish, so air is to man.
Just as we sweep our rooms, so we should sweep backward ideas from our minds.
2） as if, as though
They completely ignore these facts as if (as though) they never existed.
He looks as if (as though) he had been hit by lighting.
It looks as if the weather may pick up very soon.
说明：as if / as though也可以引导一个分词短语、不定式短语或无动词短语，例如：
He stared at me as if seeing me for first time.
He cleared his throat as if to say something.
The waves dashed on the rocks as if in anger.
原因状语从句
比较：because, since, as和for
1）because语势最强，可回答why提出的问题。当原因是显而易见的或已为人们所知，就用as或 since。
I didn't go, because I was afraid.
Since /As the weather is so bad, we have to delay our journey.
2）由because引导的从句如果放在句末，且前面有逗号，则可以用for来代替。但如果不是说明直接原因，而是多种情况加以推断，就只能用for。
He is absent today, because / for he is ill.
He must be ill, for he is absent today.
目的状语从句
可以由that, so that, in order that, lest, for fear that, in case等词引导
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.
结果状语从句
常由so… that 或 such…that引导
比较：so和 such
so foolish such a fool
so nice a flower such a nice flower
so many / few flowers such nice flowers
so much / little money. such rapid progress
so many people such a lot of people
（ so many 已成固定搭配，a lot of 虽相当于 many，但 a lot of 为名词性的，只能用such搭配。）
The boy is so young that he can't go to school.
He is such a young boy that he can't go to school
条件状语从句
连接词主要有 if, unless, as/so long as, on condition that 等。.
unless = if not.
Let's go out for a walk unless you are too tired.
If you are not too tied, let's go out for a walk.
让步状语从句
though, although
注意： 当有though, although时，后面的从句不能有but，但是 though 和yet可连用
Although it's raining, they are still working in the field.
Though the sore be healed, yet a scar may remain.
2)as, though 引导的倒装句
Child as /though he was, he knew what was the right thing to do.
= Though he was a small child, he knew what was the right thing to do.
Try hard as he will, he never seems able to do the work satisfactorily.
= Though he tries hard, he never seems…
3)ever if, even though.
We'll make a trip even though the weather is bad.
4) whether…or 不管……都
Whether you believe it or not, it is true.
5)"no matter +疑问词" 或"疑问词+后缀ever"
No matter what happened, he would not mind.
Whatever happened, he would not mind.
注意：no matter 不能引导主语从句和宾语从句。
（错）No matter what you say is of no use now.
（对）Whatever you say is of no use now.
（错）Prisoners have to eat no matter what they're given,
（对）Prisoners have to eat whatever they're given.
表示"一…就…"的结构
hardly/scarcely…when/before, no sooner…than和as soon as都可以表示"一…就…"的意思，例：
I had hardly / scarcely got home when it began to rain.
I had no sooner got home than it began to rain.
As soon as I got home, it began to rain.
注意：如果hardly, scarcely 或no sooner置于句首，句子必须用倒装结构：
Hardly / Scarcely had I got home when it began to rain.
No sooner had I got home than it began to rain.
常见考法
1.各种状语从句的基本用法；
2.时间、条件、让步状语从句中的时态变化；
3.while,whatever/however/wherever/whenever的用法；4.状语从句中省略的情况。
误区提醒
1.状语从句种类和引导词对应不上；
2.时态上犯错误；
3.不清楚省略的原则，不能正确选择；
4.no matter +wh- 和whatever等引导让步状语从句和名词性从句的用法弄混。
【典型例题】
1） ___she is young, she knows quite a lot.
A. When B. However C. Although D. Unless
解析：答案：C。意为虽然她很年轻，却知道许多，although引导让步状语从句，此题容易错选B,因为However young she is, she knows quite a lot与此句意思一样。
2）You will be late ___ you leave immediately.
A. unless B. until C. if D. or
解析：答案A。 句意：除非你立即走，否则你就会迟到的。可转化为 If you don’t leave immediately, you will be late. B、D句意不对，or表转折，句子如为 You leave immediately ____ you will be late，可选D.
3) Generally speaking, _____ according to the directions, the drug has no side effect.
A. when taken B when taking C. when to be taken D. when to take
解析：错选C. 本题考查状语从句的省略。完整句子应为 “when it is taken according to the directions,…..”。时间状语从句不用将来时（含表将来的结构），所以C选项错。正确答案为A。
4）________ , she knows a lot about football teams.
A. House wife as she is B. A house wife as she is
C. As she is a house wife D. As a house wife
解析：错选B。用as表让步时，如逻辑表语为可数名词单数，在句首不能用不定冠词。故正确答案为A。C和D选项意思上有逻辑错误，不选。
