if, whether引导的名词从句
1）yes-no型疑问从句
主语：Whether the plan is feasible remains to be proved.
Whether she comes or not doesn’t matter.
宾语：Let us know whether / if you can finish the article before Friday.
表语：The point is whether we should lend him the money.
同位语：They are investigating the question whether the man is trustworthy.
形容词宾语：She's doubtful whether we shall be able to come.
介词宾语： I worry about whether he can pass through the crisis of his illness.
2）选择性疑问从句
Please tell me whether / if they are Swedish or Danish.
I don't care whether you like the plan or not.
区别：if不能引导主语从句和表语从句；whether可以与or (not)连用，而if则一般不能。
定语从句
关系代词有：who, whom, whose, that, which等。
关系副词有：when, where, why等。
1 关系代词引导的定语从句
1）Is he the man who/that wants to see you?
He is the man whom/that I saw yesterday.
2）They rushed over to help the man whose car had broken down.
Please pass me the book whose（of which）cover is green.
3）A prosperity which / that had never been seen before appears in the countryside.
The package（which / that）you are carrying is about to come unwrapped.
2 关系副词引导的定语从句
1）There are occasions when（on which）one must yield.
Beijing is the place where（in which）I was born.
Is this the reason why（for which）he refused our offer?
2）His father died the year（that / when / in which）he was born.
He is unlikely to find the place（that / where / in which）he lived forty years ago.
3 判断关系代词与关系副词
方法一：用关系代词，还是关系副词完全取决于从句中的谓语动词。
This is the mountain village where I stayed last year.
I'll never forget the days when I worked together with you.
判断：
This is the mountain village where I visited last year.
I will never forget the days when I spent in the countryside.
This is the mountain village（which）I visited last year.
I'll never forget the days（which）I spent in the countryside.
方法二：准确判断先行词在定语从句中的成分（主、谓、宾、定、状），也能正确选择出关系代词/关系副词。
1. Is this museum ___ you visited a few days ago?
A. where
B. that
C. on which
D. the one
D
2. Is this the museum ____ the exhibition was held.
A. where
B. that
C. on which
D. the one
A
4 限制性和非限制性定语从句
1） 定语从句有限制性和非限制性两种。
This is the house which we bought last month.
The house, which we bought last month, is very nice.
2） 当先行词是专有名词或物主代词和指示代词所修饰时，其后的定语从句通常是非限制性的。
Charles Smith, who was my former teacher, retired last year.
My house, which I bought last year, has got a lovely garden.
This novel, which I have read three times, is very touching.
3） 非限制性定语从句还能将整个主句作为先行词。
He seems not to have grasped what I meant, which greatly upsets me.
Liquid water changes to vapor, which is called evaporation.
注意：关系代词that和关系副词why不能引导非限制性定语从句。
5 介词+关系词
1）介词后面的关系词不能省略。
2）that前不能有介词。
3）This is the house in which I lived two years ago.
This is the house where I lived two years ago.
Do you remember the day on which you joined our club?
Do you remember the day when you joined our club?
6 as, which非限定性定语从句
As we know, smoking is harmful to one's health.
The sun heats the earth, which / as is very important to us.
1）The weather turned out to be very good, ___ was more than we could expect.
A. what
B. which
C. that
D. it
B
2）It rained hard yesterday, ____ prevented me from going to the park.
A. that
B. which
C. as
D. it
B
注意as / which区别：a) 如果从句在前主句在后，只能用as，也就是说as可以放在句首，which不行。b) as代表前面的整个主句并在从句中作主语时，从句中的谓语必须是系动词 (be, go, get, seem, become, feel…)；若为行为动词，则从句中的关系代词只能用which。
as 的用法
I have got into the same trouble as he（has）.
As we know, smoking is harmful to one's health.
As is known, smoking is harmful to one's health.
7 先行词和关系词二合一
1）Whoever spits in public will be punished here.（Whoever可以用 anyone who 代替）
2）The parents will use what they have to send their son to technical school.（what 可以用all that代替）
8 what/whatever; that/what; who/whoever
1）whatever = anything；what = the thing which.
What you want has been sent here.
Whatever you want makes no difference to me.
2）whoever= anyone who；who= the person that.
判断：
Who breaks the law will be punished.
Whoever robbed the bank is not clear.
Whoever breaks the law will be punished.
Who robbed the bank is not clear.
3）that 和 what
I think（that）you will like the stamps.
What we need is more practice.
9 关系代词that 的用法
1）不用that的情况
a）引导非限定性定语从句时。
（错）The tree, that is four hundred years old, is very famous here.
b）介词后不能用。
We depend on the land from which we get our food.
We depend on the land that/which we get our food from.
2）只能用that作为定语从句的关系代词的情况
a）在不定代词，如：anything, everything, nothing, the one, all, much, few, any, little等作先行词时，只用that，不用which。
All that is needed is a supply of oil.
b）先行词有the only, the very修饰时，只用that。
c）先行词为序数词、数词、形容词最高级时，只用that。.
d）先行词既有人，又有物时。
状语从句
1 地点状语从句
通常由where, wherever 引导。
Where I live there are plenty of trees.
Wherever I am I will be thinking of you.
2 方式状语从句
通常由as,（just）as…so…, as if, as though引导。
1）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 looked as if（as though）he had been hit by lightning.
It looks as if the weather may pick up very soon.
注意：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。
He stared at me as if seeing me for first time.
He cleared his throat as if to say something.
3 原因状语从句
比较because, since, as和for：
1）I didn't go, because I was afraid.
Since /As the weather is so bad, we have to delay our journey.
2）He is absent today, because / for he is ill.
He must be ill, for he is absent today.
4 目的状语从句
目的状语的从句可由that, so that, in order that, lest, for fear that, in case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.
5 结果状语从句
结果状语从句由so…that或such…that引导。
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
6 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.
You will be late ___ you leave immediately.
A. unless
B. until
C. if
D. or
A
7 让步状语从句
1）though, although引导的让步状语从句，后面的从句不能有but，但though 和yet可连用。
Although it's raining, they are still working in the field.
He is very old, but he still works very hard.
2）as, though引导的让步从句必须表语或状语提前。
Child as /though he was, he knew what was the right thing to do.
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.
替换：no matter what = whatever
no matter who = whoever
no matter when = whenever
no matter where = wherever
no matter which = whichever
no matter how = however
判断：
（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.
注意：no matter 不能引导主语从句和宾语从句。 (环球网校独家资料,如需转载请注明出处)
