六大英语从句总结
- 综述
从句是复合句中相对于主句具有从属地位的分句，有自己的主语和谓语，一种特殊的句子，与正常句子的不同在于，从句须由一个关联词引导。
根据从句在句子成分中的作用，可分为名词性从句、形容词从句和副词性从句，具体分为6类从句：
- 名词性从句（包括主语从句，宾语从句，表语从句，同位语从句），在句子的功用相当于名词
- 形容词性从句（即定语从句），在句子中相当于形容词
- 副词性从句（即状语从句），在句中相当于副词
可快速记忆为：主宾表同位、定语从句和状语从句。
考试要求：初中生，要求掌握宾、表、定、状；高中生需全部掌握（另加主、同）
二、分类综述
- 名词性从句 （共4种）
- 主语从句（Subject Clause）：在主句中做主语。
- 主语从句可直接位于主语的位置，如：
When I will finish the task is unknown.
What I want is a complete holiday.
Why I couldn’t go home is the coronavirus spreading in Beijing.
That you failed the exam has been known by your mother.
How to deal with the conflict is very important to both sides.
如果从句较长，谓语又较短，可用 it作形式主语，而将从句放在句末，常见的句型有：
It is a fact\a pity\ a question\good news that...
It seems\appears\happened\has turned out that...
It is clear\important\likely\possible that...
It is said\reported\estimated\has been proved that...
It is said that comic books create a connection between people of the same generation.
It seems that the performance is very useful.
- 所有主语从句须用陈述语序，如下（3）除外，该出也为易考考点。
How the plan is to be carried out should be discussed again.
Whoever comes is welcome.
- 以what’s wrong/ the matter/ the trouble 引导的从句要保持该结构不变，须单独掌握。
What’s wrong with the car is still unknown to us.
What’s the trouble to the team workers is lacking of power and water.
- 宾语从句：在主句中做宾语，分为三类：动词的宾语从句、介词的宾语从句和形容词的宾语从句。（简称：动宾，介宾，形宾）
（1）宾语从句可位于及物动词、介词和某些形容词后，须为陈述语序。
I promised that I would change the situation.（动宾）
All this is different from what American young people say about friendship.（介宾）
He is certain that watching so much television is not good for children.（形宾）
（2） 宾语从句后如有宾补，要用形式宾语 it 来代替，而把宾语从句移至宾补之后。
He has made it clear that he would not change his mind.
I found it difficult to finish the job on time.
（3）否定前置：在 think, believe, suppose, expect 等动词后的宾语从句中，变成否定句时需在主句处进行否定。
He didn’t think that the money was well spent.
I don’t believe that he can do the homework by himself.
（4）考点：介宾句子中，通常用介词 which的形式，不用that；但是有些固定搭配除外：in that（因为），except that（除了），but that（只是），需单独记忆。
This article is well-written except that it is a bit too long.
- 表语从句：在连系动词后面用作表语，用来说明主语的身份、特征、状态等。
除可用 that, what, when, why, whether, how 等引导外，还可由 because, as if (though)等引导。
备注：that 常可省略；if不可以引导表语从句
My opinion is that you should work hard.
This is what I want to do.
The most important thing to remember is that there is no one common type of life in America.
It looks as if successful international cultural communication will make the world smaller.
特殊考点：如主句主语为 reason, 只能用 that 引导表语从句，不可用 because. 如：
The reason why many people died there is that there were not enough food supplies.（正确）
The reason why many people died there is because there were not enough food supplies.（错误，前后重复）
- 同位语从句：用于解释说明前面的名词，作用相当于该名词（短语），对其加以补充说明或进一步解释，相当于一个表语从句，它们之间的关系就是同位关系，即主表关系。
一般用连词 that 引导，由于先行名词的意义不同，也可用 whether, who, when, where, what, why, how 等引导。常见的先行名词有fact, idea, belief, news, hope, conclusion, evidence, suggestion, order, problem, report, decision等。有时由于谓语较短，为了避免句子的头重脚轻，需将同位语从句放在谓语之后。
The news that you got the first place is true.
She finally made the decision that she would join the fashion show.
I had no idea how many books I could borrow at a time.
The news came that their team had won the championship.（避免头重脚轻，从句置于句后）
- 形容词性从句，即定语从句
定语从句：是由关系代词或关系副词引导的从句，其作用是作定语，修饰主句的某个名词性成分，相当于形容词，所以又称为形容词性从句，一般紧跟在它所修饰的先行词后面，分为限定性和定于从句非限定性定于从句。
The student who answered the question was sandy. 回答问题的学生是sandy.
This is the garden where I visited yesterday.
- 副词性从句，即状语从句
相当于一个副词，修饰谓语动词，或整个句子，说明时间、地点、方式、让步、条件、比较、方式、原因等。典型特征是去掉该从句，主句依然完整，从句只是补充说明作用，具体可分为如下9种：
- 时间状语从句
引导时间状语从句的从属连词和词组有：when, whenever, while, as, after, before, since, till, until, once 等词；以及as soon as, hardly (scarcely)...when, no sooner...than, each (every) time, the moment, immediately (that) 等。
We have learnt quite a lot about it since we came here.
As soon as I sent an e-mail message, I received positive responses.
The moment he heard the good news, he jumped with joy.
When it rains, I usually go to school by bus.
- 地点状语从句
引导地点状语从句的连词是 where, wherever
Wherever she went, she took her little daughter with her.
She likes waking in the garden where there are all kinds of beautiful flowers.
- 原因状语从句
引导原因状语从句的从属连词有：because, as, since, now (that), seeing that, considering that, in that 等。
Considering that he is a freshman, we must say he is doing well.
- 条件状语从句
引导条件状语从句的连词和词组有 if, unless, as(so) long as, on condition that, in case, provided (providing) that, supposing等。
As long as you have the right equipment, you can use a telephone line to transmit computer data.
考点：If 引导的条件状语从句，其结构为：if 状语从句＋主句。要注意在该从句中有一个规则是“主将从现”，即主句是将来时，则从句要用一般现在时表示将来，如：
If he comes tomorrow, you will see him. 如果他明天来，你就可以看到他了。
- 目的状语从句
引导目的状语从句的连词有：so that, in order that, for fear that, lest 等，从句常使用 may, might, can, could, would 等情态动词。
We got up early this morning so that we could catch the first bus to the railway station.
- 让步状语从句
引导让步状语从句的连词和词组有 though, although, whether, even though, even if, no matter what (when, how...), whatever (whenever, wherever, however....)等。
No matter what you may say, I would not change my mind.
They finished the work on time though the time is very stringent.
特殊考点：Though, even if (=even though) 等引导状语从句，可转换成含有 as 的部分倒装句，具有强调意义, 其结构为“形容词（副词、动词、名词、分词） as 主语 谓语”。
Young as he is, he is quite experienced in this work. (=Though he is young)
Child as he is, he can speak English fluently. (=Though he is a child)
- 比较状语从句
比较状语从句表达人或事物的属性或特征的不同程度。常由as···as（和···一样），not as / so···（不像···那样），than（比），the···（越···越···）等引导。
Our classroom is as big as theirs.
I hope you like it as much as I do.
The speed of sounds in water is about four times as great as in air.
This book is twice as thin as that one.
Tom is no less diligent than peter.
He feels no better today than he did yesterday.
The weather is not so cold as it was last winter.
It is not as easy as you think.
The work did not go so smoothly as we hoped.
This flower is less beautiful than that one but sweeter than that one.
Man grows faster than the planet he inhabits.
- 方式状语从句
引导方式状语从句的连词有 as, just as, as if, as though 等。
考点：as if, as though 引导的状语从句中，谓语动词常用虚拟语气，表示与事实相反。
The young man made the experiment just as the teacher had taught him.
Everything went on as usual as if nothing had happened.
- 结果状语从句
引导结果状语从句的连词有：so...that, such...that, so that, that, so 等。
Mickey Mouse is so attractive that the children are reluctant to leave.
