置于动词、介词等词性后面起宾语作用的从句叫宾语从句。宾语从句的语序必须是陈述语序。谓语动词、介词、动词不定式，v.-ing形式后面都能带宾语从句。有些形容词（afraid,sure,glad等）之后也可以带宾语从句。

⒈ 宾语从句可以作及物动词、介词及形容词的宾语。

⒉ 宾语从句的语序一律用陈述句语序。

⒊ 连接词that 引导宾语从句在句中无词义，不充当句子成份，多数情况下可以省略。

⒋ whether和if都可引导宾语从句，但whether 后可紧跟or not；whether从句可作介词的宾语。

⒌ 如果从句太长，可以用形式宾语it.

在复合句中作主句的宾语，引导词有：

连词：that（that 常可省略）,whether,if

代词：who,whose,what,which

副词：when，where,how,why等。

⒈ that 引导的宾语从句（在非正式场合that 可以省略）

①可跟that从句做宾语的动词有：say,think,insist,wish,hope,demand,imagine,wonder,know,suppose,see,believe,agree,admit,deny,expect,explain,order,command,feel,dream,suggest,hear,mean,notice,prefer,request,require,propose,declare,report等。

如：The boy believes that he will travel through space to other planets.

注意：当主句谓语动词是think,believe,suppose,expect 等词，而宾语从句的意思是否定时，常把否定转移至主句表示。

如：I don't think it is right for him to treat you like that.

② 在以下情况中that不能省略

⑴ 当句中的动词后接多于两个由that引导的宾语从句时，第一个that可省，但后面的that不可省。

如：He said(that)you were too young to understand the matter and that

he was asked not to tell you.

⑵ 当主句的谓语动词与 that 宾语从句之间有插入语时，that一般不可省。

如：Just then I noticed for the first time,that our master was wearing

his fine green coat and his black silk cap.

⑶ 当that 从句是双宾语中的直接宾语时，that不可省。

如：I can't tell him that his mother died.

注意：许多带复合宾语的句子，that引导的宾语从句经常移到句子后部，而用it作形式宾语。

如：I find it necessary that we should do the homework on time.

⒉ 由whether,if引导的宾语从句

① 由whether（if）引导的宾语从句，实际上是一般疑问句演变而来的。意思是“是否”。宾语从句要用陈述句语序。一般说来，在宾语从句中whether与if可以互换使用，但在特殊情况下if与whether是不能互换的。

如：I wonder whether(if）they will come to our party.

② 只能用whether，不能用if引导的宾语从句

⑴ 在带to的不定式前

如：We decided whether to walk there.

⑵ 在介词的后面

如：I'm thinking of whether we should go to see the film.

⑶ 在动词后面的宾语从句时

如：We discussed whether we had a sports meeting next week.

⑷ 直接与or not连用时

如：I can't say whether or not thet can come on time.

③ 只能用if不能用whether引导的宾语从句

⑴ if引导条件状语从句，意为“如果”

如：The students will go on a picnic if it is sunny.

⑵ if引导否定概念的宾语从句时

如：He asked if I didn't come to school yesterday.

⑶ 引导状语从句even if（即使）和as if（好像）时

如：He talks as if he has known all about it.

⒊ 连接代词和连接副词引导的宾语从句

这样的宾语从句实际上是由特殊疑问句变化而来的，宾语从句要用陈述句语序。

用于这种结构的动词有：

see, say, tell, ask, answer, know, decide, show, find out, imagine, suggest, doubt, wonder, discover, understand, inform, advise等。

英语中的连接代词有：who,whom,whose,which,what,在句中担任主语、宾语、定语或者表语。

如：Can you tell me whom you are waiting for?

英语中的连接副词有：when,where,why,how，在句中担任状语的成分。

如：None of us knows where these new parts can be bought.

宾语从句的语序是陈述句语序即：连接代词/副词+主语+谓语+其他成分。

如：I don't know what they are looking for.

Could you tell me when the train will leave?

Can you imagine what kind of man he is?

⒈ 主句是一般现在时，从句根据实际情况使用任何时态。

如：The headmaster hopes everything goes well.

⒉ 主句是过去时态，从句须用过去时态的某种形式。

如：She was sorry that she hadn't finished her work on time.

⒊ 当宾语从句表示的是一个客观真理或者事实时，即使主句是过去时，从句也用一般现在时态。

如：The teacher told his class that light travels faster than sound.

在复合句中，修饰主句或主句谓语的句子叫作状语从句。状语从句可位于主句之前，也可位于主句之后。状语从句可分为时间、地点、原因、结果、条件、方式、让步、比较和目的等九大类。

⒈ 上述有些连词除了能引导状语从句外，还可引导定语从句和名词性从句。在使用的时候，要根据句子结构和句意来判别和区分不同的从句，正确使用引导词。以where为例，试比较下列多种从句的区别。

如：You are to find it where you left it.(地点状语从句）

Tell me the address where he lives.(定语从句，先行词为the address)

I don't know where he came from.(宾语从句）

Where he has gone is not known yet.(主语从句）

This place is where they once hid.(表语从句）

⒉ 在两个分句间要有一个且只有一个连词，千万不能按汉语习惯。

如：Because he was ill,he didn't come to school.

=He was ill,so he didn't come to school.

⒊ 在时间、地点、条件、方式或让步状语从句中，若从句的主语与主句的主语一致（或从句的主语为it），从句的谓语又包含动词be时，从句中的“主语+be”部分可省略。

如：When (he was)asked about it,he kept silent.

Fill in the blanks with articles when (they are)necessary.

If(it is)possible,I'll explain it again later.

She stood at the gate as if (she was) waiting for someone.

⒈ 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，可以表示主句的动作和从句的动作同时发生，或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 sopted 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）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。

⒉ as引导的时间状语从句

as 侧重表示主句和从句的动作并相发生，翻译成“一边……一边……”。

如：We were having breakfast as she was combing her hair.她梳头时我们在吃早饭。

⒊ while引导的时间状语从句

while或“在……期间”，所引导的从句的动作是延续性的，并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。

⒋ before引导的时间状语从句

① before“在……之前”

如：I'll be back before you have left.你离开之前我就会回来。

② before“……之后才”

如：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。

⒌ as soon as/once/directly/the instant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。

⒍ 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。

⒎ 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。

如：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。

⒏ till/until引导的时间状语从句till和until同义，作“直到……时（为止）”解，till多口语话，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(tll)I finished my homework.等我做完作业我才和你一起去。

⒈ where引导的地点状语从句，从属连词where“在（或到）……的地方”

如：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。

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。

⒉ wherever引导的地点状语从句wherever=no matter where后者只能放句首。从属连词wherever“在（或到）……的各个地方”

如：You can go wherever(anywhere)you like these day.这些天你可以去你想去的地方。

Where(no matter where)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（wherever 不可以换成no matter where）

⒈ because引导的原因状语从句

通常用于回答why引出的疑问句，语气最强，该从句一般位于主句后面。

如：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。

⒉ as引导的原因状语从句

as 引导的原因状语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, l 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。

⒊ since引导的原因状语从句

since 引导的原因状语从句多位于主句之前，通常可以和as换用。与as用法一样

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。

⒋ now（that）引导的原因状语从句，now(that)“既然”

如：Now(that) you have passed your test you can drive on your own.你既已考试合格，就可以独自开车了。

⒌ 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。

⒈so tha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，so that引导什么从句根据句意来判断

如：Suddenly it began to rain heaily, 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引导的结果状语从句

so…that“如此……以致”，that 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；such+a/an+形容词+单数名词+that=so+形容词+a/an+单数名词+that从句。

如：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。

⒈ in order that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：they 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。

⒉ so (that)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。

⒊ in case/for fear(that)引导的目的状语从句

in case for fear(that)这俩个从属连词都表示否定目的，意思是“以免”，“以防”。in case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。

如：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。

⒈ if引导的条件状语从句，翻译成“如果”

如：If I were a bird，l would fly.如果他说了那样的话，他不可能是说实话。

⒉ 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。

⒊ if only引导的条件状语从句

ifonly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。

⒋ 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。

⒌ 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 aree to go providing(that my expense are paid.)假如为我负担费用，我就同意去。

⒈ 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。

⒉ 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。

⒈ 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。

⒉ as if/as thougl导的方式状语从句

as if和as though的用法相同，都作“好像，仿佛”；二者引导的状语从句往往用虚拟语气，表示与事实相反。

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。

⒈ although/though引导的让步状语从句

although和though，都作“虽然；尽管”，通常可以换用.

如：Although they have been talking, for a long time,he can not make her believe him.虽然和她谈了半天，他还是不能让她信任自己。

⒉ 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 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。

⒊ even though导的让步状语从句

even though“虽然，尽管”，通常可以和although/though换用。

如：Even though I didn't understand a work, I kept smiling.即使我一个字也不懂，我还是保持微笑。

Even though you say so l do not believe it.即使你这样说，我也不信。

⒋ while引导的让步状语从句，while“虽然，尽管”

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。

⒌ whatever/no matter what引导的让步状语从句

Whatever=no matter what都作“无论什么”

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。

⒍ whichever/no matter which引导的让步状语从句

Whichever=no matter which都作“无论哪个”

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 purse, Barbara 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。

⒎ whoever/no matter who 引导的让步状语从句

Whoever=no matter who都作“无论谁”

如：You can't come in, whoever you are.不管你是谁，都不能进来。

⒏ however/no matter how 引导的让步状语从句

However=no matter how都作“无论如何……”

如：However high it maybe it can't reach the sky.它不论有多高，也高不到天上去。

⒐ whenever/no matter when引导的让步状语从句

Whenever=no matter when都作“无论何时”

如：Whenever I'm unhappy,he cheers me up.每当我不高兴时，他就给我鼓劲儿。

⒑ 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。

⒈ 定语从句：

在主从复合句中，充当主句的定语成分，用于修饰某一名词、代词或名词短语的从句叫定语从句。定语从句一般紧跟在它所修饰的词之后。

⒉ 先行词：

被定语从句修饰的词叫先行词。

⒊ 关系词：

引导定语从句的词叫关系词。在定语从句中代替先行词并充当一定的成分。关系词有关系代词和关系副词。关系代词有that，which，who,whom,whose等，在从句中作主语、宾语、定语和表语；关系副词有when,where，why等，时间、地点、原因状语。

关系词的选择由先行词的意思及先行词在从句中充当的成分决定。

⒈ who指人，在定语从句中作主语或宾语（口语或非正式文体中，可省略）。

如：That is the teacher who teaches us physics.

⒉ whom指人，在定语从句中做宾语，可省略。

如：Li Ming is just the boy (whom) I want to see.

⒊ which指物，在定语从句中做主语或宾语，做宾语时常可省略。

如：Football is a game which is liked by most boys.

⒋ that指人时，相当于who或whom；指物时，相当于which。在定语从句中作主语或宾语，作宾语时常可省略。

如：He is the man that/who lives next door.

Where is the man (that/whom) I saw this morning?

The season that/which comes after spring is summer.

The dress (that/which)Ann bought doesn't fit her very well.

⒌ whose指人、物皆可，在定语从句中做定语，表“某某的”。

如：I visited a scientist whose name is known all over the country.

常用以下结构来代替：

The house whose windows are broken is empty.

The house the windows of which are broken is empty.

We went to see our teacher whose husband lost his life in the earthquake.=We went to see our teacher,the husband of whom lost his life in the earthquake.

⒍ 限制性定语从句中，当先行词被such,the same修饰时，关系代词用as，译作“像……一样的人或物”。

如：He wished to be such a man as Lei Feng was.

I've never heard such stories as he tells.

注意：the same.…as和the same...that结构的句意不一样。

如：This is the same book as I read last week.

This is the same book that I read last week.

⒈ “介词+关系代词”引导的定语从句

关系代词在从句中作介词宾语时，可以把介词放在从句中有关动词的后面，使关系代词紧跟它所修饰的先行词，也可以跟介词一起放在从句与主句之间，此时，指物只能用which，指人只能用whom，关系代词是所有格时用whose。

如：The school(which/that)he once studied in is very famous.

The school in which he once studied is very famous.

This is the boy (whom/who/that)I played tennis with yesterday.

=This is the boy with whom I played tennis with yesterday.

① 含有介词的动词短语一般不拆开，介词仍放在短语动词的后面。

如：look for,look after,take care of 等。

② 介词的选择

⑴ 与从句中谓语动词的搭配相关

如：This is the book on which I spent 10 yuan.

This is the book for which I paid 10 yuan.

⑵ 与先行词的搭配相关

如：I will never forget the time during which I spent my childhood in the country.

⑶ 与所表达的意义相关

The colorless gas without which we can not live is called oxygen.

③“介词+关系代词”前还可有some,any,none,all,both,neither,many,most,each，few等代词或者数词，表示先行词的部分或整体。

如：He loves his parents deeply,both of whom are very kind to him.

⒉ that和which在指物时一般可以互换，但在下列情况中，一般用that而不用which

① 先行词本身为everything,nothing,something,anything,little,few,much,all,none,some all,the one等不定代词时

如：Everything that he said was true.

② 先行词被all,every,any,no,some,few,little,much,the very(恰恰，正好）,the only等修饰时

如：This is the very grammar book(that)I want to buy.

③ 先行词是序数词、形容词最高级或被序数词、形容词最高级修饰时

如：This is the best that has been used against pollution.

④ 先行词被the only,the very,the last修饰时

如：This is the very book that belongs to him.

⑤ 先行词既有人，又有物时

如：He mentioned the people and things that he saw in his trip.

⑥ 先行词前面有who,which等疑问代词

如：Who is the girl that you spoke to just now?

⑦ 主句是there be结构，修饰其主语的定语从句用that（先行词为物）

如：There is a book on the desk that belongs to my sister.

⑧ 先行词在定语从句中做表语，而关系代词在从句中也做表语时。

如：She is no longer the sweet girl(that)she used to be.

⒊ that和who在指人时一般可以互换，但当先行词是he,she等人称代词，以及one，ones,anybody,anyone,all,none,those等不定代词时，一般用who,不用that。

如：Those who want to go to the cinema will have to wait at the gate of the school.

⒈ when在定语从句中作时间状语（=in/at/on/during+which)

如：I'll never forget the day when/on which I first met you.

Great changes are taking place in the city where/in which they live.

⒉ where在定语从句中作地点状语（=in/at/on+which)。

situation（情景），case（实例），point（阶段），Internet，stage（阶段）等表抽象“地点”的名词作先行词时，关系副词选择where。

如：The school where/in which my son studies is near a park.

The Internet,where we can search for a large amount of information,has become an indispensable part of many people's life.

⒊ why在定语从句中作原因状语（=for+which）。

如：There are many reasons why/for which people like traveling.

如：The teacher told me that Tom was the only person that I could depend on.

China is a country which has a long history.

His mother,who loves him very much,is strict with him.

I have been to Hangzhou,which is a very beautiful city.

⒈ 非限制性定语从句引导词的选择（不能用that）

① 先行词指人，在从句中作主语，用who

如：His mother,who loves him very much,is strict with him.

② 先行词指人，在句中作宾语，用whom

如：His wife,whom you met at my horme,was a teacher.

③ 先行词指物，在句中作主语或宾语，用which

如：Her house,which was built a hundred years ago,stood still in the earthquake.

④ 先行词指人或物，在句中作定语，用whose

如：The book,whose cover is red,is mine.

⑤ 先行词在句中作时间状语，用when

如：The sports meeting will be put off till next month,when we will have made all the preparations.

⑥ 先行词在句中作地点状语，用where

如：The next day we arrived in New York,where we were interviewed on the radio.

⑦ 先行词作介词的宾语，介词+whom/which

如：The girl,with whom he is familiar,is a football player.

The Second World Warin which millions of people were killed,ended in 1945.

⒉ 关系代词as和which引导的非限制性定语从句

① as和which 都可以在定语从句中做主语或宾语，代表前面整个句子（从句谓语动词要用第三人称单数）。

如：He married her,as / which was natural.

He is honest,as/ which we can see.

② as引导的非限制性定语从句可以放在主句之前、主句之后，甚至还可以分割主句，常常有“正如、正像”的含义。which引导的非限制性定语从句，先行词是整个句子时，只可放在主句之后，意为“这一点”。

如：As is known to all,China is a developing country.

John,as you know,is a famous writer.

He is from the south,as we can see from his accent.

Zhang Hua has been to Paris more than ten times,which I don't believe.

⑴ 当主句和从句之间存在着逻辑上的因果关系时，关系词往往只用which。

如：Tom was late for school again and again,which made his teacher very angry.

⑵ 若非限制性定语从句中的谓语动词是be said,be known,be expected,be reported，等结构时，不论是在句首、句中还是句末，都必须as用来引导。

如：We won the game as we expected.

③ 以the way为先行词的限制性定语从句常由in which或that引导，而且通常可以省略。

如：The way (that/in which)he answered the questions was surprising.

在复合句中作主语的从句叫主语从句。主语从句通常由从属连词that，whether和连接代词what，who，which，whatever，whoever以及连接副词how，when，where，why等词引导。that在句中无词义，只起连接作用；连接代词和连接副词在句中既保留自己的疑问含义、又起连接作用，在从句中充当从句的成分。

如：What he wants to tell us is not clear. 

It is known to us how he became a writer. 

Where the English evening will be held has not yet been announced. 

⒈ 由连词that引导的主语从句：引导词that无含义，在句中不做成分，不可以省。

如：That you will win the medal seems unlikely.

That you are so indifferent bothers me.

That she survived the accident is a miracle.

⒉ 用连词 whether 引导的主语从句：whether有含义(是否)，在句中不做成分，不可以省。

如：Whether she is coming or not doesn't matter too much.

备注：It doesn't matter if 是固定句型。

⒈ 在由连接代词who, whose, whom, which, what, whoever, whomever, whichever, whatever引导的名词性从句中，其连接代词在句中起名词性作用，担当一定成分，有意义。

如：What you need is more practice?

What I want to know is this?

Whatever we do is to serve the people.

⒉ whatever, whoever, whichever引导的主语从句的区分：

Whatever 相当于anything that , 是 what 的强调形式，表示“无论什么”。

如：Whatever she does right.

Whoever相当于anyone who,是who 的强调形式，表示“无论谁，任何…的人”。

如：Whoever walks around in such a heavy rain will catch a cold.

Whichever“无论哪个，无论哪些”，既可以指人，也可以指物，可以单独使用，可以修饰名词，也可以后跟of短语。

如：Whichever book you borrow doesn't matter to us.

连接副词when, where, why, how引导的主语从句中，其=连接副词有含义，在句中作状语。

如：Where we should leave it is a problem.

When they will come hasn’t been made pubic.

有时为避免句子头重脚轻，常用形式主语it代替主语从句作形式主语放于句首，而把主语从句置于句末，但是不能代替由what引导的主语从句。主语从句后的谓语动词一般用单数形式。常用句型如下：

⑴ It + be + 名词 + that从句     

⑵ It + be + 形容词 + that从句

⑶ It + be + 动词的过去分词 + that从句

⑷ It + 不及物动词 + that 从句

另注意在主语从句中用来表示惊奇、不相信、惋惜、理应如此等语气时，谓语动词要用虚拟语气“(should) +do”，常用的句型有：

It is necessary (important, natural, strange, etc.) that…

It is a pity (a shame, no wonder, etc.) that…

It is suggested (requested, proposed, desired, etc.) that…

在复合句中作表语的从句叫表语从句。引导表语从句的关联词与引导主语从句的关联词大致一样，表语从句位于连系动词后，一般结构是“主语+连系动词+表语从句”。可以接表语从句的连系动词有：be, look, remain, seem等。注意：关联词不能省略，并且从句用陈述语序。

如：The fact is that we have lost the game. 

That is why he didn't come to the meeting.  

需要注意的，当主语是reason时，表语从句要用that引导而不是because。但是reason 后面的定语从句可以用why 或that引导。

如：The reason why he was late was that he missed the train by one minute this morning .

⒈ that在名词性从句中不充当句子成分，只起连接作用，没有意义，不能省略（在宾语从句中能省略）。

如：That they are good at English is known to us all.

The problem is that we don't have enough money.

⒉ what在名词性从句中充当句子成分，起连接作用，有意义，不能省略。what可以分解成定语从句中的先行词 + 关系代词+ that。理解为双重身份。

如：Do what he says.

What (=The thing that) he said was true.