英语从句（Subordination）
英语从句主要有定语从句，状语从句和名词性从句（主语从句，宾语从句，表语从句，同位语从句）
一．定语从句
1． 定语从句：由关系代词 who, whom, whose, that, which; 关系副词 when, where, why 引导。
1. The death notices tell us about people who have died during the week.
2. The man (whom) you spoke to just now is my friend.
3. The building whose lights are on is beautiful.
4. Please find a place which we can have a private talk in.
5. The knee is the joint where the thighbone meets the large bone of the lower leg.
6. He still remembers the day when he went to school.
7. It is no need telling us the reason why you didn't finish it in time.
8. He has three sons, two of whom died in the war.
9. Mr. Smith, whose wife is a clerk, teaches us English.
10. In the Sunday paper there are comics, which children enjoy.
2． 只能用that和who引导的定语从句
A．all, nothing, anything, a few, one做先行词指物时
B．先行词前有形容词最高级修饰时，后面常跟that而不是which.
C．先行词前有 the only, the first, the last, the next, the very等词修饰时，引导词只能用that。
D．当先行词是 anyone, anybody, everyone, everybody, someone, somebody时，后面要用who或whom；
● All that glitters is not gold. 闪光的并非都是金子。
3． as 引导定语从句
as 引导的定语从句有两种形式：
A．引导限制性语从句。
在此类定语从句中，as常与主语中作为其先行词的such, the same或as联用构成，“such... as”，“the same... as”和“as ...as”句型，可代替先行词。
例如：We hope to get such a tool as he is using. 我们希望得到他正在用的那种工具。
B．as 引导非限制性定语从句时，作用与which相同，as作为关系代词代替整个主句。
［注意区别］：
as 引导的从句用于句首、句中或句后，而which引导的定语从句不能放在句首。
例如：As is reported, a foreign delegation will visit the city.
二．状语从句
① 原因：because, since, now that（既然）as, for, this reason....
② 结果：so that, so, therefore, consequently, so as to, as a result ....
③
时间：after, before, when, while, as, until, as soon as, since, by the
time, once, lately, presently, shortly after, currently, at present,
nowadays ...
④ 条件：if, only if., once, unless, in the event (that), in case (that), provided that, on the condition that, etc.
⑤ 让步：though, although, even though(if), no matter what / how / when→ whatever / however / whenever ....
⑥ 目的：in order that, in order to, to,
⑦ 比较：than, as ... as, by comparison（相比较），by contrast（相对照）....
三．名词性从句
通常由 that或疑问词导出。
1. How some mammals came to live in the sea is not know.（主语从句）
2. The attorney told his client that they had little chance of winning the case.（宾语从句）
3. The problem is what we'll do next.（表语从句）
4. We have no idea that he has come back.（同位语从句）
同位语（Appositive）:
同位语是英语语法的重点内容，也是各类考试中的一个考点，同时，在写作中正确运用同位语可以使你的句型更加简洁得体。
When
reports came into London zoo that a wild puma had been spotted
forty-five miles south of London, they were not taken seriously.
（当伦敦动物园接到报告说，在伦敦以南45英里处发现一只美洲狮时，这些报告并没有受到重视。）
在这里，a
wild puma had been spotted forty-five miles south of
London就是同位语从句，它本来应该放在 “reports”后面，这里却被放在了谓语成分 came into London
zoo的后面，目的是让句型显得更为稳重。
I．简单记忆：同位语从句，就是对某些名词做进一步的解释的句子。
I was greatly shocked when I heard the news that his father died yesterday.
（that 引导的句子解释了news的内容，注意：that不做任何成分）
We have to face the fact that the weather is unexpectedly bad.
（that 引导的句子解释了fact的内容）
II．联想记忆：
能接同位词从句的名词有：belief（信仰），fact，idea，doubt，rumor（谣言），evidence（证据），conclusion（结论），suggestion（建议），problem，order，answer，discovery（发
现）explanation（解释），principle（原则），possibility（可能性），truth，promise（承诺），report（报告），statement（声明），knowledge（知识），opinion（观点），likelihood（可能性）
III．要点：
● 同位语一般由that引导，但也可以用关系代词which, who, what和关系副词when, where, why, how或 whether 引导。
There arouse the question whether we could win the game.
I have no idea howto explain it.
● 一些介词词组后面也能引导同位语从句。（非常经典之功能句式，可用于四六级和托福作文，不妨一试！）：
on the assumption（在……前提下），
on the ground（由于……原因），
on the condition that（在……条件下），
with the exception（有……例外）
owing to the fact（由于……事实）；
on the understanding（基于……理解）；
The young lady promised to marry the old man on the condition that he bought her a villa.
IV．分隔式同位语从句
为了使句型平衡不至于头重脚轻，有时同位语从句可以放到句子的末尾
An idea came to him that he might write to her to ask more information about the matter.
I got information from my friend that there will be a marvelous American movie "Titanic".