在初中英语中，主要有三大从句，即宾语从句、定语从句、状语从句（包括时间、条件、结果、目的、原因、让步、地点、方式等）。
今天跟大家分享的就是这三个从句的主要语法点，赶快看起来吧！
宾语从句
一、定义
在句子中起宾语作用的从句叫做宾语从句。
二、连接词
that: I think that you can pass the exam.
Whether/if: I don’t know what the word means.
Wh: I don’t know what the word means.
I don’t know where he found the book.
只用whether的情况：
1. 与or not连用：
I don’t know whether it’s raining or not.
2. 与动词不定式连用：
He doesn’t know whether to accept the invitation.
3. 连接词前有介词时：
It depends on whether he is coming.
三、时态
1. 主句是一般现在时态，从句根据实际情况而定(各种时态均可)
She wants to know what he has done for the exam.
2.主句是一般过去时态，从句用相应的过去的时态。
1）She said that she was a student.
2）She said that she would fly to Japan in a week.
3）She said that she had finished her homework already.
3. 如果宾语从句说的是客观真理、自然现象或事实时，这时宾语从句要用一般现在时态。
The teacher said that the earth goes round the sun.
定语从句
一、定义
在复合句中修饰名词、代词的从句叫定语从句。
二、先行词
先行词指人 who /that
先行词指物 which/ that
定语从句一般紧跟被修饰的名词或代词（即先行词）后
三、关系代词
关系代词代替先行词在句子中担当成分，所以从句中不可再出现其他代替先行词的代词
四、翻译方法 …. 的
Whom:先行词指人，则代替先行词在定语从句中充当宾语（包括介词的宾语）, 与who的区别是如果前面带介词则必须用whom
1. This is the teacher whomwho we like best.
2. I don’t like the boy to whom you are talking.
Whose :指人或物，作定语，表示 …的
eg: Harry is the boy whose mother is our math teacher.
关系代词只能 that 的特殊情况：
1.先行词前有序数词修饰时：
This is the first gift that my parents bought me.
2.先行词前有形容词最高级修饰时：
This is the most exciting film that I have ever seen.
3. 先行词是不定代词something, anything等时.
e.g. Is there anything that you want in this shop
4. 先行词是人和物时, 用that.
e.g. He talked about some writers and books that were unknown to us all.
5. 先行词被all , little , the only , the very(就是，正是), the last 等词修饰时,只能用that
e.g. This is the last place that I want to visit.
6. 特殊疑问句以who 或which 开头，只能用that引导.
Who is the girl that is making a speech on the platform?
当关系代词前使用介词时：
物+介词+which ; 人+ 介词 + whom
当关系代词前使用介词时：
e.g. 1. This is the train by which we went to Beijing.
2. This is the teacher to whom my mother is talking.
状语从句
一、定义
在复合句中由从句表示的状语称作状语从句，它可以用来修饰谓语（包括非谓语动词）、定语或状语，或是整个句子。
二、状语从句一般分为八大类
时间状语从句 地点状语从句
原因状语从句 目的状语从句
结果状语从句 条件状语从句
方式状语从句 让步状语从句
1. 时间状语从句
When---当……时候, 通常指某一特定的时间点，主句与从句的动作同时发生。
When I opened the window, I saw him come up.
When--- 正在……的时候，突然…。通常主句是进行时或 be about to 时，在翻译的时候，when 可以译成没想到或突然。
I was walking along the street , when I met him.
When 当从句是进行时，主句是一般时，往往表示不满。
Someone knocked at the door when I was having breakfast.
When=after
When the children had gone to bed, she began to prepare her lessons.
While---在……期间，往往指一段时间。
While we were inAmerica, we saw him twice.
While---表示一种不满情绪，意思是这边在干某种重要的事，而另一边在享受等。
We are cleaning the classroom while they are playing the football.
As--- 一边……一边, 随着
She was doing her homework as she was listening to the music.
As--- 当……时，指一个动作紧接着一个动作发生，从句通常用进行时。
As I was going out, it began to rain.
The moment--- 一……就…… =as soon as , immediately,
---Did you remember to give Mary the money you owed her?
---Yes, I gave her the moment I saw her.
Not… until--- 直到……才
He didn’t leave the office until he finished the work.
Before--- 在……之前
The passengers should arrive at the airport an hour before the flight departs.
After--- 在…… 之后
The customer left the ticket counter after he had a quarrel with the ticket agent.
Since---自从……, 通常主句用现在完成时
I have never been there again since I graduated from the university.
It is just a week since we arrived here.
As soon as--- 一……就……
Jack went to school as soon as he got well.
No sooner than--- 一……就……
no sooner… than… 用于句首要求倒装
Hardly …when…
Scarcely …when…
No sooner had he arrived than he went away again.
Once--- 一但……就……
Once you see him, you will never forget him.
Every time, each time每次whenever每当
Each time he came to town, he would visit our school.
2. 条件状语从句
引导状语从句的连接词有：
If如果, unless除非, as long as只要, As (so) far as --- 据……所知，in case万一, provided that假如, on condition that若是，以…为条件
If---如果
If you don’t hurry up, you will miss the plane.
Unless--- 如果不, 除非=if not
We can’t get there on time unless we book the earliest flight
As long as--- 只要
We will succeed as long as we keep on trying.
As (so) far as--- 据……所知
As far as I know, he speaks English very well.
In case--- 假使, 如果
The plane cannot take off in case it rains.
Provided that如果,有时省略 that
The plane will be in good condition provided that it is taken care of carefully.
On condition that--- 条件是…
He said that he would come to the meeting on condition that no one asked him to speak.
注:主从句的动作发生在将来时，则主句用将来时, 从句用一般现在时。
If he arrives tomorrow, I will be waiting for him at the airport.
3. 地点状语从句
地点状语从句只有两个连词: Where, wherever
Where--- 在……地方
Where there is a will, there is a way.
Wherever--- 无论哪里
Wherever you are, I will be right there waiting for you.
4. 原因状语从句
because, as, since, now that, 和considering that, seeing that 这六个连词都用于表示表示原因, 但在语气上一个比一个弱.
Because--- 因为,通常从句放在主句后.
Mr Smith was very upset because he couldn’t find his luggage.
As--- 因为, 通常放在句首
As he is honest and modest, all his friends like him.
Since---既然 因语气较弱, 常译为既然(众所周知的原因)
Since everybody has come, we can set off.
Now that--- 既然
Now that you are here, you can join us.
considering that--- 顾及到
Considering that they are just beginners, they are doing quite a good job.
seeing that--- 由于
Seeing (that) quite a few people were absent, we decided to put the meeting off.
5. 结果状语从句
引导结果状语从句的连词有：that, so that, so…that…
such…that So… that--- 太……以至于 so 后面应用形容词或副词, 有时省略so只用that
Boeing 747 is so large that people like to call it jet bomb喷气炸弹.
So that--- 因而，以便，为了 有时so 可以省去
Speak louder please so that the people at the back can hear you.
Such …that…---太……以至于 用法与so…that相同，但such 后面应用名词。
The foreign visitor was such a fast speaker that nobody could understand him.
6. 目的状语从句
引导目的状语从句的主要连词有: that, so that, in order that, for fear that, lest
(So) that--- 以便, 从句中常常使用一些情态动词，如：can, could, may, might, should等
Let’s take the front seats (so) that we may see more clearly.
in order that--- 为了, 与so that 相同从句中常常使用一些情态动词，如：can, could, may, might, should等
School was closed early in order that the children might go home ahead of the storm.
for fear that--- 生怕; 为了防止(某事发生)
He took the name down for fear that he should forget it.
in case--- 万一
You should bring a dictionary in case you need it.
Lest--- 以防万一
The man decided to tell his boss the fact lest he would be angry with him.
7. 让步状语从句
引导让步状语从句的连词有：Although, though, as, even if, even though, no matter, however, whatever, while, whether.
Although, though---虽然 although 和though 可以互换，但although 常放在句首。Though可以用于倒装。
Although it was raining, the plane managed to take off.
Though he did his best, he didn’t succeed.
As--- 尽管 as 引导让步状语从句时，句子通常倒装。可与though 互换。
Busy as he is, he never misses a football match.
Even if /even though---即使
Even if you don’t like your boss, you should do your work.
However--- 不论， however 引导让步状语从句时，句子通常倒装
He couldn’t get there on time however fast he drove.
No matter (what, when, where, how)---无论（什么，何时，何地，怎样）
He wouldn’t forgive me no matter how hard I begged him.
Whatever--- 不管
Whatever other people may say, she won’t change her mind.
While---尽管
While I have sympathy for you, I can’t help you.
Whether---不管，常与or not 连用
Whether he is good or not, the company decided to send him abroad.
8. 方式状语从句
方式状语从句常由: as, as if, as though
as---与…… 一样
Do in Rome as the Romans do.
as if, as though--- 仿佛, 由as if或 as though引导的从句中可用虚拟语气
She stood at the door as if (=as though) she were waiting for someone.
