状语从句：
指句子用作状语时，起副词作用的句子。它可以修饰谓语、非谓语动词、定语、状语或整个句子。
根据其作用可分为时间、地点、原因、条件、目的、结果、让步、方式和比较等从句。
状语从句一般由连词(从属连词)引导，也可以由词组引起。
从句位于句首或句中时通常用逗号与主句隔开，位于句尾时可以不用逗号隔开。
状语从句分类:
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 mother was until I became an adult.
While John was watching TV, his wife was cooking.
The children ran away from the orchard(果园) the moment they saw the guard.
No sooner had I arrived home than it began to rain.
Every time I listen to your advice, I get into trouble.

2、地点状语从句
常用引导词：
where
特殊引导词：
wherever, anywhere, everywhere
Generally, air will be heavily polluted where there are factories.
Wherever you go, you should work hard.

3、原因状语从句
常用引导词：
because, since, as, for
特殊引导词：
seeing that, now that, in that, considering that, given that, considering that, as much as, so much as
My friends dislike me because I'm handsome and successful.
Now that everybody has come, let's begin our conference.
The higher income tax is harmful in that it may discourage people from trying to earn more.
Considering that he is no more than 12 years old, his height of 1.80 m is quite remarkable.

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 that
The boss asked the secretary to hurry up with the letters so that he could sign them.
The teacher raised his voice on purpose that the students in the back could hear more clearly.

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.
To such an degree was he excited that he couldn't sleep last night.

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 that
We'll start our project if the president agrees.
You will certainly succeed so long as you keep on trying.
Provided that there is no opposition, we shall hold the meeting here.

7、让步状语从句
常用引导词：
though, although, even if, even though
特殊引导词：
as(用在让步状语从句中必须要倒装),while ( 一般用在句首 ),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.
尽管我很尊敬他, 我却不同意他的建议。
The old man always enjoys swimming even though the weather is rough.
No matter how hard he tried, she could not change her mind.
He won't listen whatever you may say.

8、比较状语从句
常用引导词：
as(同级比较), than(不同程度的比较)
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; not A so much as B
She is as bad-tempered as her mother.
The house is three times as big as ours.
The more you exercise, the healthier you will be.
Food is to men what oil is to machine. 食物之于人,犹如油之于机器。

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.
Sometimes we teach our children the way our parents have taught us.

状语从句用法:
时间状语从句
(1) when引导的时间状语从句
①.when引导的时间状语从句，其动词既可以是延续性动作的动词，也可以是瞬间性动作的动词，而且可以表示主句的动作和从句的动作同时发生，或者从句的动作发生在主句的动作之前。如：
when you apply for a job, you must present your credentials.
当你申请工作时，你必须递交你的有关证件。（同时）
when the students heard the teacher’s footsteps, they all atopped talking.
当学生们听到老师的脚步声时，他们都停止了讲话。（从句动作发生在前）
② when还可表示just then（正在那时，突然）的意思，此时其所引导的从句只放在主句之后。如：
we were about to start when it began to rain.
我们正要动身，突然天下起雨来。
The game had hardly/scarcely/barely begun when it started raining.
比赛刚刚开始就下起雨来。
(2) as引导的时间状语从句
as引导的时间状语从句其动词的动作是延续性的，而且侧重表示主句和从句的动作并相发生：
We were having breakfast as she was combing her hair.
她梳头时我们在吃早饭。
It will warm up a little bit on Sunday as the cold front passes.
寒流一过，星期日就会有点暖意了。
(3) while引导的时间状语从句
while表示“在某一段时间里”或“在……期间”，其所引导的从句的动作是延续性的，并侧重表示和主句的动作同时发生。如：
When the teacher paraphrased the text in English, the students listened attentively and took notes.
当老师用英语解释课文时，学生们聚精会神地听并做着笔记。
I can learn while I work.
我可以边工作边学习。
(4) before引导的时间状语从句
① before“在……之前”
I have finished my dissertation before my supervisor went abroad.
在我的导师出国之前，我已完成了我的学位论文。
I’ll be back before you have left.
你离开之前我就会回来。
② before“……之后才”
It may be many years before we meet again.
可能要过许多年我们才能再见了。
It was three days before I came back.
他三天后才回来。
(5) as soon as/once/directly/the instant等引导的时间状语从句
as soon as 是最常见的表示“一……就”的从属连词，其他连词还有once，directly，immediately，instantly，the instant (that)，the minute(that) ，the moment(that)等，它们通常都可与as soon as换用。如：
As soon as we got home, the telephone rang.
我们一到家，电话就响了。
I recognized her immediately I saw her.
我一看见她就认出她来了。
Directly the teacher came in everyone was quiet.
老师一进来，大家就静了下来。
(6) hardly...when/no sooner...than引导的时间状语从句
关联从属连词hardly/barely/scarcely...when和no sooner...than的意思是“刚……就”，它们所引导的从句中的谓语动词通常为过去完成时。如：
He had no sooner (no sooner had he)arrived home than he was asked to start on another journey.
他刚一到家，就又要他出另一次差。
No sooner had the words been spoken than he realized that he should have remained silent.
这些话刚一出口，他就意识到自己应该保持沉默。
(7) since引导的时间状语从句
在含有since引导的时间状语从句的复合句中，从句的谓语动词通常为一般过去时，主句的谓语动词通常为现在完成时、过去完成时和一般现在时：
We’ve never met since we graduated from the college.
大学毕业后我们就再没见过面。
Great changes have taken place since you left.
你走了以后，这里发生了巨大变化。
(8) till/until引导的时间状语从句 till和until同义，作“直到……时(为止)”解，till多用于非正式文体，until多用于句首。如：
Donald will remain in college until(till) he finishes his Ph.D course.
唐纳德将留在学校直到完成他的博士学位课程。
I won’t go with you until(till) I finished my homework.
等我做完作业我才和你一起去。
(9) whenever/each time/every time引导的时间状语从句
whenever在引导时间状语从句时作“每当；每次”解，each time和every time与whenever同义，通常可以与它换用。如：
The roof leaks whenever it rains.
每逢下雨屋顶就漏雨。
Whenever certain chemicals are mixed together，heat is produced.
某些化学物质被混到一起时，就会产生热。
Whenever/ Every time/ Each time I met her, she was studying.
我每次看见她时，她总是在学习。

状语从句 - 地点状语从句
(1) when引导的时间状语从句
从属连词where“在（或到）……的地方”
Where there is a will, there is a way.
有志者事竟成。
Put it where you found it.
把它放在原来的地方。
① where 在地点状语从句中，除指地点外，还可指处境等。如：
He said he was happy where he was.
他说他对自己的处境很满意。
It’s your fault that she is where she is.
她今天落到这个地步都怪你。
② 有时地点状语从句中的某些词可以省略。如：
Fill in the blanks with the given phrases. Change the form where necessary.
用所给的短语填空，必要的地方可以改变其形式。
Avoid structure of this kind where possible.
只要可能，就要避免这种结构。
(2) wherever引导的地点状语从句
从属连词wherever“在（或到）……的各个地方”：
You can go wherever(anywhere) you like these days.
这些天你可以去你想去的地方。
Where (Everywhere) they went, the experts were warmly welcomed.
专家每到一处， 都受到热烈的欢迎。
Sit down wherever you like.
你喜欢坐哪儿就坐哪儿。

状语从句 - 原因状语从句
 (1) because引导的原因状语从句
because表示人们不知道的直接的原因或理由，着重点在从句，其所引导的从句，为全句句意的中心所在。
通常用于回答why引出的疑问句，语气最强，除特别强调外，该从句一般位于主句后面。
I didn’t go abrord with her because I couldn’t afford it.
我没有和她一起出国是因为费用太高。
Don’t scamp your work because you are pressed for time.
不要因为时间仓促而马马虎虎。
(2) as引导的原因状语从句
as引导的原因状语从句所传递的通常是已知信息，从句多位于主句之前，通常可以和since换用。如：
As I didn’t know the way，I asked a policeman.
我不认识路，因而问警察。
As it is snowing, we shall not climb the mountain.
由于在下雪，我们不去爬山了。
(3) since引导的原因状语从句
since引导的原因状语从句所传递的通常是已知信息，从句多位于主句之前，通常可以和as换用。如：
Since traveling by air is much faster,they decided to take a plane.
既然乘飞机旅行快得多，他们就决定坐飞机。
Since you won’t help me ，I’ll ask someone else.
你既然不帮我，那我就请别人帮忙。
(4) now(that)引导的原因状语从句
now(that)“因为；既然”，通常可以和since换用。其中that可省去，用来表示一种新的情况，再加以推论。如：
Now(that) you?蒺ve passed your test you can drive on your own.
你既已考试合格，就可以独自开车了。
I do remember，now (that) you mention it.
你这一提，我倒的确想起来了。
(5) seeing (that)引导的原因状语从句
Seeing (that)“鉴于；由于”，通常用于非正式文体。如：
Seeing (that) the weather is bad，we’ll stay at home.
天气不好，我们还是呆在家里吧。
Seeing that he’ s ill，he’s unlikely to come.
(6) in that引导的原因状语从句
in that“因为；基于……的理由”，可以和because换用，多用于正式文体，它所引导的原因状语从句总是位于主句之后。如：
Advertisement is distinguished from other forms of communication in that the advertiser pays for the message to be delivered.
广告不同于其他交际形式，因为登广告的人要为其所提供的信息付费。
I’m in a slightly awkward position, in that he’s not arriving until 10th.
我的处境有点难堪，因为他要十号才来。

状语从句 - 目的状语从句
 (1) in order that引导的目的状语从句
in order that“为了；以便”。多用于正式文体，通常可以与so that换用。如：
You stopped at Hangzhou in order that they could go around West Lake.
他们在杭州停了下来，以便游览西湖。
The expert spoke slowly in order that everyone should understand.
专家讲得很慢，以便人人听得懂。
(2) so (that)引导的目的状语从句
so that“为了；以便”。so that通常可以与in order that换用，它所引导的目的状语从句总是放在主句之后，在非正式文体中，常省略that。如：
Speak clearly so that they may understand you.
你要讲得清楚，他们才听得懂。
She wanted tea ready at seven so she could be out by eight.
她要七点钟备好茶点，这样她八点以前就可以出门了。
(3) in case/for fear (that)/lest等引导的目的状语从句
in case，for fear(that)和lest这三个从属连词都表示否定目的，意思是“以免”,“以防”。
in case多用于英国英语，它所引导的从句中的谓语动词可以是陈述语气形式，也可以是虚拟语气形式；
for fear(that)引导的从句中的谓语带有may，might，should等情态动词；
lest用于正式文体，它所引导的从句中的谓语动词用虚拟语气形式。如：
Take your umbrella with you，lest it should rain.
带上你的伞，以防下雨。
Take your umbrella in case it rains.
带上你的伞，以防下雨。
He took an umbrella with him for fear that it might rain.
他带了一把伞，以防下雨。
状语从句 - 结果状语从句
(1) so that引导的结果状语从句
① so that引导的结果状语从句只能位于主句之后，中间可以有逗号。如：
Suddenly it began to rain heavily，so that it was almost impossible to carry on driving.
突然下起了大雨，几乎无法继续开车。
Linda phoned me in on arrival so that I know she was safe and sound.
琳达到达后给我打了电话，因而我知道她平安无事。
②“so that”既可引导结果状语从句也可引导目的状语从句。
究竟是引导的结果状语从句还是目的状语从句，除了根据句意来判断外，还可根据结构形式来加以判断。
若从句前有逗号，一般为结果状语从句，如果从句中有情态动词，通常则为目的状语从句。如：
They started out early, so that they didn’t miss the train.
他们早早就出发了，所以没误火车。(结果状语从句)
They started out early so that they would not miss the train.
他们早早出发是为了不误火车。(目的状语从句)
(2) so...that引导的结果状语从句
so...that“如此……以致”，that在非正式文体中可以省略，so后面接形容词或副词。如：
She spoke so fast that nobody could catch what she was saying.
她说话如此之快竟没有人听出来她在讲什么。
There is so little time left that I have to tell you about it latter.
现在剩下的时间不多了，我只好以后再给你讲这件事。
(3) such...that引导的结果状语从句
引导结果状语从句的such...that的具体内容是：such+a/an+形容词+名词+that从句。
其中的名词可以是可数名词的单数或复数，也可以是不可数名词。
such+a/an+形容词+单数名词+that从句可换成so+形容词+a/an+单数名词+that从句。如：
The Japanese student made such rapid progress that he soon began to write article in Chinese.
那个日本留学生进步很快，不久就开始用中文写文章了。
The professor told us such a funny story that all the students laughed．
(＝The professor told us so funny a story that all the students laughed.)
教授讲了个很有趣的故事，(以致于)所有的学生都笑了起来。
(4) such that引导的结果状语从句
such that引导的结果状语从句多用于正式文体，主句为“主—系—表”句型。如：
The force of the explosion was such that it blew out all the windows.
爆炸的力量很大，所有的窗户都被炸掉了。
His anger was such that he lost control of himself.
他气得不能克制自己的感情。

状语从句 - 条件状语从句 
(1) if引导的条件状语从句
if可引导非真实条件状语从句(见“虚拟语气”)和真实条件状语从句。如：
If he said that，he can’t be telling the truth.
如果他说了那样的话，他不可能是说实话。
(2) unless引导的条件状语从句
unless引导的是否定条件状语从句，在意义上相当于if...not，而且语气较强，一般不用于虚拟语气。如：
You’ll be late unless you hurry.
你会迟到的，如果不赶快的话。
(3) if only引导的条件状语从句
if only在引导条件状语从句时意为“只要；如果”。如:
I’ll let you use the car if only you keep it in good condition.
只要你把车保养好，我就让你用。
(4) as/so long as引导的条件状语从句
as/so long as意为“只要；如果”。如：
As long as it doesn’t rain, we can play.
只要不下雨我们就能玩。
(5) provided (that)/providing (that)引导的条件状语从句
provided (that)/providing (that)意为“如果；只要”。如：
I will agree to go provided’ providing (that my expense are paid.)
假如为我负担费用，我就同意去。
Providing you promise not to tell anyone else I’ll explain the secret.
状语从句 - 让步状语从句
(1) although/though引导的让步状语从句
although和though，都作“虽然；尽管”解，通常可以换用，although的语气较重。
如果要强调“但是”语气，可使用yet，still或nevertheless来表示“但是”、“依然”或“然而”之意。
Although they have been talking for a long time, he cannot make her believe him.
虽然和她谈了半天，他还是不能让她信任自己。
(2) even if引导的让步状语从句
even if “即使，纵然”，从句表示的是尚未发生的动作或存在的情况。如：
Even if it rains tomorrow，we won’t change our plan.
即使明天下雨，我们也决不改变计划。
Even if I failed again, I will not give up the experiment.
即使我再次失败，我也决不会放弃实验。
(3) even though引导的让步状语从句
even though“虽然，尽管”，从句所表示的是已经发生的动作或存在的情况，通常可以和although/though换用。如：
Even though I didn’t understand a word，I kept smiling.
即使我一个字也不懂，我还是保持微笑。
Even though you say so，I do not believe it.
即使你这样说，我也不信。
(4) much as引导的让步状语从句
much as“虽然，尽管”，通常可以和although/though换用：
Much as I’d like to，I can’t come.
我虽然很想来，但是来不了。
Much as I admire his courage，I don’t think he acted wisely.
我虽然佩服他的勇气，但我认为他这样做是不聪明的。
(5) while引导的让步状语从句
while“虽然，尽管”，多用于正式文体，通常可换作although/though。如：
While I understand your point of view，I do not share it.
我虽了解你的观点，但不敢苟同。
While I sympathize，I really can’t do very much to help.
虽然我很同情，但我确实帮不了什么忙。
(6) whatever/No matter what引导的让步状语从句
whatever和no matter what用法相同，都作“无论什么”解，后者多用于非正式文体。如：
Whatever/No matter what he says，don’t go.
不管他说什么，你都不要走。
We are determined to fulfill the task，whatever/no matter what happens.
不管发生什么了，我们决心完成任务。
(7) whichever/no matter which引导的让步状语从句
whichever和no matter which用法相同，都作“无论哪个”解，后者多用于非正式文体。如：
Whichever/No matter which you buy， there is a six-month guarantee.
不论你买哪个，都有六个月的保修期。
Whichever/No matter which of the two men had stolen her purseBarbara was determined to find them.
不管这两个人是谁偷了她的钱包，芭芭拉决心找到他们。
(8) whoever/no matter who引导的让步状语从句
whoever和no matter who用法相同，都作“无论谁”解，后者多用于非正式文体。如：
You can’t come in， whoever you are.
不管你是谁，都不能进来。
Whoever/No matter who wants to speak to me on the phone, tell him I’m busy.
不管谁要我接电话， 就说我现在正忙着呢。
(9) whereverno matter where引导的让步状语从句
wherever和no matter where用法相同，都作“无论在（或到）哪里”解，后者多用于非正式文体。如：
Wherever/No matter where you go, I’m Right Here Waiting fo ryou.
无论你到哪里，我都依然在这里等着你。
(10) however/no matter how引导的让步状语从句
however和no matter how用法相同，都作“无论如何……”解，后者多用于非正式文体。
However much you regret doing that， there is nothing you can do about it now.
无论你可能多么懊悔你曾经做过的事，现在也无济于事了。
However high it may be，it can’t reach the sky.
它不论有多高，也高不到天上去。
(11) whenever/no matter when引导的让步状语从句
whenever和no matter when用法相同，都作“无论何时”解，后者多用于非正式文体。如：
Whenever I’m unhappy，he cheers me up.
每当我不高兴时，他就给我鼓劲儿。
(12)(no matter) whether...or引导的让步状语从句
whether...or和no matter whether...or用法相同，都作“不论……还是”解，后者的语气强一些。如：
When It Rains or not, we’re playing football on Sunday.
无论下不下雨，我们星期天一定踢足球。
(13) as引导的让步状语从句
as在引导让步状语从句时作“虽然；尽管”和“即使”解，但是它不位于句首，在它前面的可以是形容词、名词、副词等。如：
Strong as you maybe, you cannot lift it.
虽然你可能很有力气，你却无法把它提起来。
Late as it was, they continued to study.
时间尽管不早了，他们仍继续学习。

状语从句 - 方式状语从句
(1) as引导的方式状语从句
as在引导方式状语从句时意为“以……方式；如同……那样”，从句有时是省略句。如：
Do as I say. 要照我说的做。
I did just as you told me. 我正是照你说的办的。
Air is to man as water is to fish. 空气之于人犹如水之于鱼。
(2) as if/as though引导的方式状语从句
as if和as though的用法相同，都作“好像，仿佛”解。如：
二者引导的状语从句往往用虚拟语气，表示与事实相反。as if比as though更为常用。
但也可用陈述语气，表示所说的情况是事实或实现的可能性较大。如：
They looked at me as if ‘as though I were mad.
他们瞧着我好像我发疯了似的。
They look as if/as though they know each other.
他们看来好像互相认识。

状语从句 - 比较状语从句
(1) as...as 引导的比较状语从句
as...as表示同级比较，主句中用形容词或副词的原级形式，从句常常为省略句。如：
We were as fortunate as them (they were)
我们和他们一样幸运。
I hope she will make as much progress as you (have done).
我希望她将取得和你同样的进步。
(2) not so/as...as 引导的比较状语从句
not so/as...as表示同级比较，主句中用形容词或副词的原级形式，从句常常为省略句。如：
That’s not so/as simple as it sounds.
那件事情不像听起来那么简单。
(3) than引导的比较状语从句
than引导的比较状语从句表示同等比较，主句中用形容词或副词的比较级形式，从句常常为省略句。如：
He has lived here longer than I(has lived).
他在这儿住的时间比我长。
They love the girl than(they love) him.
他们爱这个女孩而不爱他。
(4) the..., the...引导的比较状语从句
The more you listen to English, the easier it becomes.
英语听得越多就越容易。

虚拟语气:
用来表示说话人的主观愿望或假想，而不表示客观存在的事实，所说的是一个条件，不一定是事实，或与事实相反。
虚拟语气通过谓语动词的特殊形式来表示。
初中阶段主要学习在条件句中的虚拟语气。
条件句中的虚拟语气根据不同的时间有三种不同的形式。

时间	条件从句	主句	例句
与现在事实相反	If+主语+过去式（系 动词be多用were）	would 主语+should+V原  could	见①②句
与过去事实相反	If+主语+had+过去分词	Would 主语+should+have+过     去分词  could	见③④句
与将来事实相反	过去式     If+主语+ should+V原  were to+V原	would 主语+should+V原   could	见⑤⑥句

例句：
① If I were rich, I would travel around the world.
② If I won a million dollars, I would give it to charities.
③ If you had taken my advice, you wouldn’t have failed.
④ If I had known that earlier, I wouldn’t have done it. 
⑤ If he should go to Tsinghua University, he would make full use of his time.
⑥ If he were to come here, he would tell us about it.

虚拟语气误区:
1.混合条件句的主从句时态不会灵活变化；
2.省略if时，句子调整不正确；
3.不会去找意思中的“应该”含义；
4.陷在虚拟中出不来，把真实条件句当成虚拟条件句。

省略虚拟条件:
1.省略连词if
有时可将条件从句的连词if省略，但此时应用倒装句型，即把从句中的were,should,had 等提到句首：
Were I Tom,I would refuse. 如果我是汤姆，我会拒绝。
Should it be necessary,I would go. 假若有必要，我会去的。
Had it not been for the bad weather we would have arrived on time. 若不是天气坏，我们就准时到达了。
【注】
① 若条件从句为否定句，否定词not应置于主语之后，而不能与were,should,had 等缩略成Weren’t,Shouldn’t,Hadn’t而置于句首。
② 有时省略if后提前的had不是助动词：
Had I time,I would come. 假若我有时间，我会来的。(=If I had time…)

2.省略主语和动词be
若主从句主语一致，且谓语部分包含有动词be，通常可将主语和动词be省略：
If repaired earlier,the tractor would not have broken down.
要是早点儿修一下，拖拉机就不会抛锚了。(=If it had been repaired earlier…)

3.省略“it+be”
If necessary,I would send more farmhands to help you.
如果需要的话，我会派更多的人去帮你。(=If it was necessary,…)

4.省略条件从句
这样的省略通常需要借助一定的上下文，即省略条件从句后，所剩下的主句的意思在一定的上下文中意思是清楚的：
I might see her personally. It would be better.
我可以亲自去看她，这样好一些。(=If I saw her personally,it would be better.)

含蓄条件句中
(1) 条件暗含在短语中。如：
We didn’t know his telephone number; otherwise we would have telephoned him.
我们不知道他的电话号码，否则我们就会给他打电话。（暗含条件是otherwise）
Without your help,we wouldn’t have achieved so much.
没有你的帮助，我们不可能取得这么大的成绩。
（暗含条件是介词短语without your help）
But for your help,I would not have succeeded in the experiment.
如果没有你的帮助，我的实验就不会成功。（暗含条件是but for your help）
It would cause great trouble not to lubricate the bearing immediately.
不立即润滑轴承就会引起很大的故障。
（暗含条件是not to lubricate the bearing immediately）
(2) 条件暗含在上下文中。如：
I would not have done it that way.
我是不会那么做的。（可能暗含if I were you）
I was busy that day. Otherwise I would have come to help you.
我那天很忙。否则我会来帮你的。（可能暗含if I hadn’t been so busy.）
You might come to join us in the discussion.
你可以参加我们的讨论。（可能暗含if you wanted to）
I would have bought the DVD player.
我是会买下那台影碟机的。（可能暗含if I had the money）
But for the storm,we should have arrived earlier.
要不是碰到暴雨，我们还会早些到。（可能暗含if it had not been for the storm）。

条件状语从句用法及动词形式:
1、表示与现在事实相反的情况：
从句：If 主语+过去时(Be动词用were)
主句：主语+should/would/could/might+do
eg：　
1．If I were you,I would take an umbrella.
如果我是你，我会带把伞。（事实：我不可能是你）
2．If I knew his telephone number,I would tell you.
如果我知道他的电话号码，我就会告诉你。（事实：不知道）
3．If there were no air or water,there would be no living things on the earth.
如果没有水和空气，地球上就不会有生物。(事实：地球上既有空气也有水)
4．If I had any money with me,I could lend you some.
如果我带钱了，我就会借给你些。（事实：没有带钱）
5．If he studied harder,he might pass the exam.
如果他再努力些，就能通过考试了。（事实：没有努力）
6．she looked at me as if I had been a stranger.
她看我的样子好像我是一个陌生人。（事实：我并非陌生人）　
2、表示与过去事实相反的情况
从句：If 主语+had+done
主句：主语+should/would/could/might+have done
eg：
1．If I had got there earlier,I should/could have met her. 如果我早到那儿，我就会见到她。（事实：去晚了）
2．If he had taken my advice,he would not have made such a mistake. 如果他听我的劝告的话，就不会犯这样的错误了。（事实：没有听我的话）
3、表示对将来情况的主观推测
主句：主语+should+do　
从句：
①if+主语+were to do
②if+主语+should/would/could/might+do
③if+主语+did（动词过去式）/were
eg：
1．If he should come here tomorrow,I would talk to him.
如果他明天来这儿的话，我就跟他谈谈。（事实：来的可能性很小）
2．If there were a heavy snow next Sunday,we would not go skating.
如果下周日下大雪，我们就不能去滑冰了。（事实：下雪可能性很小）
3．If she were to be here next Monday,I would tell her about the matter.
如果她下周一来这儿的话，我就会告诉她这件事的始末。（事实：来的可能性很小）
4、 有时，虚拟条件句中，结果主句和条件从句的谓语动作若不是同时发生时，虚拟语气的形式应作相应的调整。这种条件句叫错综条件句。
①从句的动作与过去事实相反，而主句的动作与现在或现在正在发生的事实不符。
eg：
If I had worked hard at school,I would be an engineer,too.
如果我在学校学习刻苦的话，我现在也会成为一个工程师了
If they had informed us,we would not come here now.
如果他们通知过我们的话，我们现在就不会来这里了。
②从句的动作与现在事实相反，而主句的动作与过去事实不符。如：
If he were free today,we would have sent him to Beijing.
如果他今天有空的话，我们会已经派他去北京了。
If he knew her,he would have greeted her.
要是他认识她的话，他肯定会去问候她了。
5、 当虚拟条件句的谓语动词含有were,should,had时，if可以省略，这时条件从句要用倒装语序，即把were,should,had等词置于句首，这种多用于书面语。eg：
Should he agree to go there,we would send him there.
要是他答应去的话，我们就派他去。
Were she here,she would agree with us.
如果她在这儿的话，她会同意我们的。
Had he learnt about computers,we would have hired him to work here.
如果他懂一些电脑知识的话，我们已经聘用他来这里工作了。
6、非真实条件句中的条件从句有时不表达出来，只暗含在副词、介词短语、上下文或其他方式表示出来，这种句子叫做含蓄条件句，在多数情况下，条件会暗含在短语中，如without…，but for…等　　
eg：
But for his help,we would be working now.
要不是他的帮助，我们还会在工作呢。
Without your instruction,I would not have made such great progress.
要是没有你的指导，我不会取得如此大的进步。
We didn't know his telephone number,otherwise we would have telephoned him.
我们不知道他的电话号码，否则我们就会给他打电话。
7、有时，虚拟条件句中，主、从句可以省略其中的一个，来表示说话人的一种强烈的感情。
①省略从句
He would have finished it. 他本该完成了。
You could have passed this exam. 你本能通过这次考试的。
②省略主句
If I were at home now. 要是我现在在家里该多好啊。
If only I had got it. 要是只有我得到它了该多好啊。
8.注意，在虚拟语气的从句中，动词be的过去时态一律用were，不用was。
eg：If I were you,I would go to look for him.
如果我是你，就会去找他。

虚拟语气的其他用法:
1、一想要( desire )
一宁愿( prefer )
一坚持( insist )
二命令( order , command )
三建议( advise , suggest , propose/recommend)
四要求( demand , require , request , ask)中，
无论主句谓语动词为何种时态，从句的谓语动词都用："should + do"。should可以省略。
eg：
He suggested that we (should) take the teacher's advice.
He insisted that we (should) take the teacher's advice.
He demand that we (should) take the teacher's advice.
He ordered that we (should) take the teacher's advice.
insist 意为“坚持某种动作”才用虚拟语气；意为“坚持某种观点，某个事实”则不用虚拟语气。eg：
He insists he is a student.
他坚持说他是个学生。
这个语句表示的是事实，因此在这个语句中不能使用虚拟语气。
suggest意为“建议”才用虚拟语气，意为“暗示”则不用虚拟语气。
eg：
His face suggests that he looks worried .
他的表情暗含着他很担心。
这个句子本身是事实，因此它就没有用到虚拟语气。
2、表情绪、观点的形容词或名词也要用虚拟语气。如：
necessary、important、impossible、natural、strange、surprising、funny、right、wrong、better、a pity ,the shame ,no wonder等。
句型：It is.......that +主语从句，从句的谓语动词都要用 should+原型或 只用动词原型。
eg:
Do you think it is necessary that he (should)not be sent to Lingbao.
It is strange that such a person should be our friend.
奇怪的是这样一个人会成为我们的朋友。
注：这一点还没有准确的说法，希望善心人能把这点补充完全。
3、 在even if,even though 所引导的让步状语从句中用may/might+动词原形，may/might可以省略，表示与现在相反的情况；
从句用过去完成时，表示与过去相反的情况，类似的词有though/even though/whatever/however/so long as; 主句、从句的结构与if所引导的条件从句结构相同。
eg：
Even if he were here himself,he should not know what to do.
即使他亲自来也不知该怎么办。（事实：他没来）
Nobody could save him even though Hua Tuo should come here.
即使华佗在世也救不了他。（事实：华佗不在世）
4、 在whatever，whichever，whenever，whoever,wherever，however,no matter wh-等引导的让步状语从句中，从句虚拟语气结构为：指现在或将来：may +do。
eg：
We will finish it on time no matter what may happen.
不管发生什么事，我们都要按时完成。
We will find him wherever he may be.
无论他在哪里，我们都要找到他。
I will wait for him no matter how late he may come.
不管他来的多么晚，我都会等他。
指过去：may +have done 。
eg：
You mustn't be proud whatever great progress you may have made.
不管你取得了多么大的进步，你也不能骄傲。
We must respect him no matter what mistakes he may have made.
不管他犯过什么错误，我们必须尊敬他。
5、一般would rather,had rather,would sooner等之后的宾语从句常表示与客观事实不相符的一种愿望，故使用虚拟语气。其虚拟语气的结构为：
过去 had + done　
现在 过去时(be 用were )
将来 过去时(be 用were ) （would rather 将来情况用一般过去时）
eg：
I'd rather you had seen the film yesterday.
我倒想你昨天看过了这场电影。
I'd rather you were here now.
我倒想你现在在这儿。
We'd rather you went here tomorrow.
我们倒想你明天去那儿
注：注意would rather，had rather，would sooner的细微差别，可以百度一下查查。
6、虚拟语气还可用在定语从句中，表示：“早该做某事了”时，定语从句中的谓语动词须用虚拟语气，其虚拟语气的结构为：
It is (high / about) time that + 主语+ 动词的过去式/ should + do（优先使用动词过去式） ，即从句用虚拟过去式。
It is time that I went to pick up my daughter at school.
我该去学校接我的女儿了。
It is high time you should go to work.
你早该上班了。
7、 简单句中的虚拟语气
（1） 说话时，为了表示客气、谦虚、委婉而有礼貌，言语常使用虚拟语气。其虚拟语气的结构形式常为：would / could / might / should +do。
eg：
Would you mind me shutting the door?
你介意我把门关起来吗？
You should always learn this lesson by heart.
你要把这个教训牢记于心。
I should agree with you.
我本该同意你的观点。（委婉的不同意）
（2）表示“祝愿”时，常用may + 主语+ do。
eg：
May you have a good journey!
祝你一路顺风。
May your youth last forever!
祝你青春永驻。
（3）表示强烈的“愿望”、“祝愿”时，常用do。
eg：God bless us. 上帝保佑。
（4）习惯表达中常用的虚拟语气。
① 提出请求或邀请。eg：
Would you like to have a talk with us this evening?
今天晚上来跟我们聊天好吗？
Could I use your bike now?
我可以用一下你的单车吗？
② 陈述自己的观点或看法。eg：
I should be glad to meet you.
见到你我会很高兴。
I would try my best to help you.
我会尽力帮助你。
③提出劝告或建议。eg：
You'd better ask your father first.
你最好先问一问你的父亲。
You should make a full investigation of it first.
你应该先全面调查一番。
④ 提出问题。eg：
Do you think he could get here on time
你认为他能按时来吗？
Do you expect he would tell us the truth?
你期望他会告诉我们真相吗？
⑤表示对过去情况的责备时，常用虚拟语气。其虚拟语气的结构为：情态动词 + have done。
eg：
You should have got here earlier. 你早该到这里了。
You should have returned it to him. 你早该把它还给他了。
8、虚拟语气在方式状语从句的应用。详见百度百科之方式状语从句词条。

固定搭配：
英语中的固定搭配主要是指英语中的习惯用法，如有固定用法的一些动词短语、介词短语、名词词组及形容词词组。
例如：
take part in (参加) 
by accident (偶然地) 
lucky dog (幸运儿)
be interested in (对…感兴趣)

初中英语常见固定搭配：
(一)加-ing
enjoy / like doing sth 喜欢做----    
spend....(in) doing sth 在做---花费---  
try doing 试着做------                
be busy doing sth 忙于做------
finish doing sth 完成做----           
look forward to + doing sth 期待做----(现在进行时)
be doing 正在做---     
Thank you for (doing) sth 为了--感谢你

（二）加-to
decide to do sth 决定去做-----             
ask (sb)to do 要求(某人)去做----      
It’s+adj +to do sth . 做---(怎么样)        
would like / want to do 想要做-----    
It takes sb sometime to do sth在做----花费----

（三）加原形
let / make sb do sth 让某人做某事   
be going to / will do sth （一般将来时态）

（四）加-to 或-ing意思不同
forget doing 忘记做过了-----(已做)    
forget to do 忘记去做------(还没做)   
remember doing记得做过了-----(已做)
remember to do记得去做------(还没做)

（五）加-to 或-ing意思相同
begin / start to do sth = begin / start doing sth开始做------

（六）
A）动词+ 介词
agree with同意....的意见(想法)；符合    
help ... with ...帮助(某人)做(某事)  listen to听...              
..get to到达....       
fall off (从......)掉下base on以....(为)根据     
knock at /on敲(门、窗)        
laugh at嘲笑
learn.. from 向...学习     
live on继续存在；靠...生活 
look after照顾，照看look at看；观看           
look for寻找             
look like看起来像
pay for (sth.)付钱；支付 
point at指示；指向          
point to指向....prefer to ...宁愿(选择);更喜欢           
quarrel with (和某人)吵架
regard...as ...把....当作....；当作                 
stop...from阻止.....做.....
talk about说话；谈话；谈论                        
talk with与......交谈think about考虑                                  
think of认为；想起
B)动词+ 副词                                                     
ask for请求；询问       
carry on坚持下去；继续下去     
cut down砍倒 
clean up清除；收拾干净  
come down下来；落    
come along来；随同
come in进来            
come on来吧；跟着来；赶快 
come over过来；顺便来访           
come out出来；出现；(花)开；发(芽)      
drop off放下(某物)；下车                              
eat up吃光；吃完
fall behind落在......后面；输给别人            
fall down跌倒；从......落下
find out查出(真相)                                
get back回来；取回
get down下来；落下；把......取下来             
get off下来；从......下来get on上(车)               
get up起床                
give up放弃go on继续               
go out出去     
go over过一遍；仔细检查
grow up长大；成长      
hand in交上来                
hurry up赶快
hold on (口语)等一等；(打电话时)不挂断             
look out留神；注意
look over (仔细)检查                            
look up向上看；抬头看  
pass on传递；转移到....                          
pick up拾起；捡起
put away放好；把....收起来  
put on穿上；戴上；(戏剧等)上演；放(唱片等
put down把(某物)放下来                             
put up挂起；举起
run away流失；逃跑；逃走 
rush out冲出去 
set off出发；动身；
启程send up发射；把......往上送  
shut down把......关上      
sit down坐下
slow down减缓；减速      
take off脱掉(衣服)          
take out取出
throw about乱丢；抛撒                          
trip over (被......)绊倒
try on试穿(衣服、鞋等)；试戴(帽子等)                
try out试验；尝试
turn down关小；调低        
turn on打开(电灯、收音机、煤气、自来水等
turn off关(电灯、收音机、煤气、自来水等)           
turn over (使)翻过来
wake up醒来                               
wear out把......穿旧；磨坏
work out算出；制订出                               
write down写下....
C) be + 形容词+ 介词                                              
be angry with对(某人)发脾气              
 be interested in对......感兴趣 
be able to能；会                                   
 be afraid of害怕
be amazed at对......感到惊讶            
be excited about对......感到兴奋
be filled with用......充满                            
be full of充满......的
be good at =do well in在....方面做得好；善于             
be late for迟到
be made in在......生产或制造            
be made of由....组成；由....
be pleased with对......感到满意              
be proud of以......自豪/高兴
be used for用于
D)动词+ 名词/ 代词                                               
beg one′s pardon请原谅；对不起         
do morning exercises做早操
do one′s homework做作业                                           
enjoy oneself =have a good time过得快乐；玩得愉快                   
give a concert开音乐会     
go boating去划船      
go fishing去钓鱼go hiking去徒步旅行     
go skating去滑冰     
go shopping (去)买东西
have a cold (患)感冒    
have a cough (患)咳嗽  
have a headache (患)头痛  
have a try尝试；努力    
have a look看一看         
have a rest休息 
have a seat (= take a seat ) 就坐；坐下        
have sports进行体育活动  
have supper吃晚餐   
hear of听说   
hold a sports meeting举行运动会
make a decision作出决定  
make a mistake犯错误  
make a noise吵闹
make faces做鬼脸      
make friends交朋友       
make money赚钱
take one′s place坐某人的座位；代替某人的职务                       
teach oneself (=learn by oneself ) 自学                  
watch TV看电视 
take photos照相       
take time花费(时间)         
take turns轮流
E)动词+ 名词/ 代词/ 副词+ 介词                                  
catch up with赶上           
come up with找到；提出(答案、解决办法等)
get on well with与......相处融洽                   
give birth to生(孩子) 
help yourself / yourselves to自取；随便吃   
make room for给.....腾出地方
play a joke on戏弄人；对人恶作剧              
speak highly of称赞   
say good bye to告别；告辞               
take an active part in积极参加
take care of照顾；照料；注意
F)其他类型                                                        
be awake醒着的          
be born出生         
be busy doing忙着做
come true实现     
do one′s best尽最大努力     
fall asleep睡觉；入睡  
go home回家    
go on doing (sth.)继续做某事；尽力   
get married结婚
get together相聚                  
go straight along  沿着...一直往前走
had better (do)最好(做...)                    
keep doing sth.一直做某事        
make sure确保；确认；查明               
make up one′s mind下决心