1.引导表语从句的从属连词主要有that，whether等。

注意if不能引导表语从句。

2.“it +连系动词+表语从句”，常用于本结构的V主要有appear，seem等3.引导表语从句的连接副词主要有who，what，which等4.引导表语从句的连接副词主要有when，where，why，how等5.有时as，as if，as though 和because也可以引导表语从句例句：The suggestion is that they should start from beginning.提出的建议是，他们从头开始。

What they want to know is whether he is capable of holding that important post.他们想知道的是他是否有能力保住那一重要职位。

It appears that you’re right.看来你是对的。

It seems that no one know what had happened.似乎没有人知道发生了什么事。

The problem is who will stay.问题是谁留下来。

What she wants to know is which dress she should buy.她想知道的是她应该买哪件衣服。

Is this where we turn off for Hull这是我们要转向赫尔的方向That is why I’m working hard at my lesson.就是这个原因，我要努力学习That is how I figured it.据我看就是这样。

Things are not always as they seem to be.事情并不总像表面上看来那样。

The sky looks as if it would clear off soon.天空看来马上就会放晴了。

It sounds as though there is a knock at the door.听起来好像有人在敲门。

练习she couldn’t understand was fewer and fewer students showed interest in her lesson.A.What ; whyB. That ; whatC. What ; becauseD. Why ; that答案：A一般由that, whether, when, how 等连接代词或what, why等连接副词引导，常放在fact, news, idea, truth, hope, problem, question, information，discovery, promise, doubt 等抽象名词后面，说明该名词的具体内容。

例句This discovery disproves the idea that the world was flat.这个发现驳斥了地球是扁平的看法。

You must live with the fact that you are no longer as strong as you were.你必须承认，你已经不像过去那么健壮了。

I have good hope that he will soon be well again.我坚信他不久就会康复。

We must have your promise that you’ll keep it to yourself.你必须答应我们你会保守秘密。

We have received information that they may have left the country.我们已经得到消息，他们可能已经离开了这个国家。

Answer my question whether you agree to my decision.回答我的问题，你是否同意我的决定。

She was in doubt whether she was right.她对她是否正确拿不准。

I have no idea when he will be back.我不知道他什么时候回来。

The police have a good idea how most of the cannabis that is introduced into the country gets past the Customs.警方非常了解传入该国的大部分印度大麻是如何通过海关的。

Have you any idea what they are worrying about你知道他们在担心什么吗Nobody can explain the mystery why he suddenly disappeared.没有人能解开他突然消失的这个谜。

练习：was shown into a small room there was a dying man.A. whichB. whereC. hereD. that2. We have worked out a scheme should save the company several thousand pounds a year,A. whichB. , whichC. whereD. that one答案：BA例句：（1）The man who telephoned was a friend of yours.打电话的人是你的一位朋友。

The custom dates from the times when men wore swords.该习俗始于人类佩带刀剑的时代。

Xi Er was at last discovered in a cave where she had been living for many years.最后人们终于在一个山洞里找到了喜儿，她在那里已经住了多年了。

（2）The patient, who had been asleep for nearly three hours , began to move his limbs.病人睡了将近3小才开始动一动胳膊和腿。

This could be the winning game for the challenger, who only needs two more points for the championship.这场比赛可能是挑战者获胜，他只要再得到两分就得冠军了。

Watch for our new improved product, which will be on the market next week!等着看我们新改进的产品吧，它们将于下星期开始在市场上出售！The journey, which I remember well, was very pleasant.我清楚地记得那次旅行很愉快。

有无逗号不同意思1.He had two sons who(that) became lawyers. 限制性他有两个当律师的儿子（其含义是也许还有更多的孩子）He had two sons , who became lawyers. 非限制性他有两个儿子，他们都是当律师（含义：只有两个儿子）the books which (that) had pictures in them were sent to the little girl. 限制性所有有图画的是都寄给了那个小女孩。

（含义：小女孩只得到那些有图画的书，可能还有别的书）All the books , which had pictures in them , were sent to the little girl. 非限制性所有的书都寄给了那个小女孩。

（含义：小女孩得到所有的书）同位语从句和定语从句区别练习：can be no doubt he is qualified for the job.A. thatB. whichC. whereD. whenis the boy is speaking thereA. whomB. thatC. whichD. whofact he is an orphan is well-known.A. whatB. whichC. thatD. whose答案：ABC例句：（1）The fact that you are talking about is very important.你所谈论的情况非常重要。

The fact that there are no lives on the moon is known to us all.在月球上没有生命存在是众所周知的事实。

I have read the news that is carried in today’s paper.我看到的这则消息刊登在今天的报纸上。

I’ve read the news that he will go abroad.我看到的这则消息说他要出国（2）The days when/on which we had to rely on “foreign oil” are gone. 我们不得不依靠外国石油的日子已经过去了。

This is the factory where/in which China’s first tractor was made.这家工厂制造出中国第一台拖拉机。

I have no idea where they are.我不知道他们在哪里。

He didn’t give the answer why he was late.他并没有回答他为什么迟到。