结构充当句子的某一(些)成分, 如主语, 宾语, 表语, 定语, 状语, 同位语等.
1. That the earth goes around the sun is known to all.
( = It is known to all that the earth goes around the sun. )
2. Whether she will come is up to her boss.（此时不能用if）
It is reported that…
It must be pointed out that…
It is likely that…
It happens that…
1. He believed that walking under a ladder brings bad luck.
2. You can learn what you do not know from the class.
3. Let me know which of the books is the best.
1. The assumption is that things will improve.
2. China is not what it used to be.
而且that在从句中不充当任何成分。这些抽象名词有：news, idea, fact,
doubt, evidence, promise, rumor, hope, truth, belief, message等，
1. The news that our football team at last defeated Korea made
the fans wild with joy.
The news that made the fans wild with joy was from the radio.
2. There is much evidence that the crime rate in this city is on
引导定语从句的引导词有关系代词（who, whom, which, that, whose）和
关系副词(as, when, where, why)等。但是当下列情况出现时，对引导词有
1. 当先行词是all, everything, nothing, something, little, much时；
当先行词被all, no, some, any, every, a few, a little, much, only,
All that you want are here.
There is no person that doesn't make mistakes. 没有人不犯错误。
his is the best book that I have ever read.
2. "the same ...as", "such...as"中的as可以指人或物，作从句的主语、
Such money as he earned was spent on spirits and tobacco.
Is this the same mosquito as bit you just now?
He was not half such a coward as we took him for.
the reason why…is that…，或者the reason that…is that…，如：
He did not tell us the reason why he was late again.The reason why
（that）he didn't come is that he was ill.
4. 当定语从句为there be句型时，关系代词只能用that。
This is the only that there is a read cover.
Who is the girl that is talking to Tom.
We are talking about the people and countries that we have visited
在"介词+which / whom"的结构中，介词的选择取决于三种情况：
This is the college in which I am studying.
He is the man about whom we are talking.
respect, area, field等，用in which；当先行词表示"价格、利率、速度"时，
如：rate, price, speed等，用at which；当先行词表示"程度"时，如：degree,
foundation, basis等，用on which
The speed at which the machine operates is shown on the meter.
It is useful to be able to predict the extent to which a price change
will affect supply and demand.
3. 当定语从句为最高级时只能用of which，否则用其他介词
I have five dictionaries of which Longman Dictionary is the best.
I have five dictionaries among which Longman Dictionary is the best.
当先行词为表示时间的名词（如：time, day, year, week, month, occasion）
或地点的名词（如：place, room, city, country）时，一般用关系副词when和
where.分别相当于in which, at which, on which。但是当这些表示时间或地点
I can't forget the days when (in which) I lived with you.
Can you tell me the day when (on which)the first satellite was sent
China is the only country where (in which ) wild pandas can be found.
I'll never forget the village where I spent my childhood.
I will never forget the days that (which) I spent in Beijing
University. (本句days作spend的宾语，故用关系代词that / which )
I have never been to Beijing, but it's the place that I most want to
非限定性定语从句不能用that引导, 一般用引导词which / as或who（指人），
As we all know, the moon is a satellite of the earth.
His speech, which bored us to death, was over at last.
Her sister, who lived in another city, was coming to visit her.
1．时间状语从句常用引导词：when, as, while, as soon as, while, before,
after, since , till, until 特殊引导词：the minute, the moment, the
second, every time, the day，the instant, immediately , directly,
no sooner…than, hardly…when, scarcely…when
I didn't realize how special my father was until I was 18.
2．地点状语从句常用引导词：where 特殊引导词：wherever, anywhere,
Wherever you go, you should work hard.
3．原因状语从句常用引导词：because, since, as, since 特殊引导词：
seeing that, now that, in that, considering that, given that, considering
that, inasmuch as, insomuch as
The higher income tax is harmful in that it may discourage people from
4．目的状语从句常用引导词：so that, in order that特殊引导词：lest, in
case, for fear that，in the hope that, for the purpose that, to the end
The boss asked the secretary to hurry up with the letters so that he
could sign them.
5．结果状语从句常用引导词：so…that, so…that, such…that 特殊引导词：
such that, to the degree that, to the extent that, to such a degree that
He got up so early that he caught the first bus.
It's such a good chance that we must not miss it.
6．条件状语从句常用引导词：if, unless 特殊引导词：as / so long as, only
if, providing/provided that, suppose that, in case that, on condition
We'll start our project if the president agrees.
7．让步状语从句常用引导词：though, although, even if, even though特殊引
no matter…, in spite of the fact that, while, whatever, whoever,
wherever, whenever, however, whichever
Much as I respect him, I can't agree to his proposal.
特殊引导词：the more…the more…, just as…, so…; A is to B what /
as X is to Y, no…more than, no…less than, A not so much as B
She is as bad-tempered as her mother.
9．方式状语从句常用引导词：as, as if, how特殊引导词：the way When in
Rome, do as the Roman do.
She behaved as if she were the boss.