必修3-unit4主语从句1
主语从句
【教学内容】主语从句
【教学目标】熟练掌握不同连接词引导的主语从句
【教学重难点】连接词的使用、It 作形式主语的常见句型
【教学过程】
●什么是主语从句：在主句中起主语作用的从句称为主语从句。
Eg:I need a good meal.(I是主语）
What I need is a good meal.（What I need 整句话作主语）
●其连接代词主要有三类：
①从属连词：that,whether,if
②连接代词：who(ever),whom(ever),whose(ever),what(ever),which(ever)
③连接副词：when(ever),where(ever),how(ever),why
▼that 引导的主语从句
①that 置于句首的主语从句
从属连词that 在主语从句中不作任何成分，也没有实际意义，只起连接作用。
→That he will come to the conference has excited every one of us.
他要来参加会议这使我们每一个人都十分激动。
→That in some countries women are still treated unequally is unfair.
在一些国家妇女仍然受到不平等对待是不公平的。
②形式主语it 替代主语从句
常见的it 替代主语从句的句式主要有如下几种：
► It+be+形容词（certain,clear,necessary,likely,obvious,probable,etc.)+that从句：
→It is certain that most of the farmers have brought in more money by all means.
很明确大多数农民通过各种方式赚了很多钱。
→It is likely that there will be a snowstorm tomorrow.
很可能明天会有一场暴风雨。
► .It+be+名词性词组（no wonder, an honour,a pity,no surprise,etc.)+that 从句
→It is a pity that we can’t go.遗憾的是我们不能去。
→It is no surprise that our team should have won the game.我们队获胜不足为奇。
► It+be+过去分词（said,reported,thought,expected,announced,etc.)+that从句
→It is thought that he has made much money by selling cigarettes.人们认为他靠卖香烟赚了很多钱。
→It is reported that the coral reefs(珊瑚礁）are being destroyed.据报道，珊瑚礁正遭受破坏。
►It+seems/happens/happened等不及物动词及短语的相应形式+that从句
→It seems that Alice is not coming to the party at all.好像Alice 根本就不会来参加聚会。
→It appears that we won’t be laid off after all.看起来我们根本就不会被解雇。
【随即随练】
用以It 作形式主语的句型翻译一下句子
（1）他可能告诉了她一切。
It is probable that he told her everything.
（2）吸烟危害健康，这是事实。
It is a fact that smoking is a danger to health.
（3）据说格林先生已经到了北京。
It is said that Mr.Green has arrived in Beijing.
（4）碰巧那天我不在。
It happened that I was out that day.
▼主语从句中的虚拟语气
（1）“It is(was)+形容词（或过去分词）+that 从句”结构中的虚拟语气
使用某些表示建议、请求、命令等形容词后的主语从句的谓语用虚拟语气。其表达形式为”should+动词原形’或者省去should ，直接用动词原形。
●常用的形容词：natural/advisable/better/necessary/important/urgent/possible/desirable/strange
●常用的过去分词：required/demanded/requested/desired/suggested/recommended/ordered
Eg:①It is necessary that we (should) have a walk now. 我们有必要去散步。
②It is required that nobody (should) smoke here. 要求不能在此吸烟。
③It is suggested that a doctor should be sent for immediately.建议马上派人去叫医生。
（2）It is +名词+that的主语从句中，常用虚拟语气表示建议、命令、请求、道歉、怀疑等。
●这类名词有
advice,decision,desire,demand,idea,motion,order,pity,preference,proposal,recommendation,requirement,resolution ,shame,suggestion,surprise,wish,wonder.,
Eg:It is my proposal that he (should) be sent to study further abroad.我建议派他去国外进一步学习。
▼含有tha t 主语从句的句子的疑问形式
该类句型的疑问形式和普通句子的一般疑问形式一样，把be 、助动词或情态动词提至主语从句或形式主语it 之前。
→Was it decided that they started the project the next month?他们下个月开始这项工程已经决定了吗？ →Did it happen to you that you had been out when he called?他打电话时，你正好不在家吗？
▼If/Whether 引导的主语从句
Eg:这项工作能否按时完成还不确定呢。
Whether the work can be completed on time is doubtful.(只能用whether )
It is doubtful whether/if the work can be completed on time.(whether/that都可以）
析：whether 引导的主语从句可置于句首，但由if 引导的主语从句不能置于句首，只能放于主句句末。
▼wh -类连接词引导的主语从句
* 当Wh -类的引导词为连接代词who,whom,whose,what,which 时
Eg:→①what we should do next remains unknown.我们下一步该干什么还不知道。（what 在句中作do 的宾语，what 从句在功能上相当于一个名词，常译作“„„的事/话/地方/时间/„„”）
②Who will come to teach us in not known.谁来教我们还不知道。（who 作主语）
③Whom we must study for is a question of great importance.我们必须为谁而学习是一个很重要的问题。（whom 作study for的宾语）
④Whose watch was lost is unknown.不知道是谁的手表丢了。（whose 作定语，译为“谁的„„”） ⑤Which team will win the game is still unknown.哪个队将赢得比赛仍然还不知道。（译为“哪个，哪些”
析：连接代词在在从句中作名词的作用，作主语、宾语、表语、定语等。
* 当Wh-类的引导词为连接副词when,where,why 时
Eg:→①When he comes has not been decoded yet.他什么时候来还没有决定. （when 作时间状语）
②Where we can go for a trip is still unknown.我们去哪里旅游还不知道。（where 作地点状语）
③Why they didn’t come is still unknown to us.我们仍旧不知道他们为什么没有来。（why 作原因状语） 析：连接副词在从句中起副词的作用，作状语。
* 连接代词whoever,whatever,whichever,wherever ，whomever 引导的主语从句
①Whoever comes will be welcomed.无论谁来都将受到欢迎。（作主语）
②Whatever he did was right.他所做的一切都是对的。（作did 的宾语）
③Whichever of you comes in will receive a prize.你们中无论哪个进来都将获得一份奖品。
④Wherever you are will not effect my love for you.无论你在哪都不影响我对你的爱。（作地点状语） ⑤Whomever you invite will be welcome.无论你邀请谁都会受到欢迎的。（作invite 的宾语）
析：这类词引导的主语从句，在句中都有“无论„„”的意思，在句中不含疑问意义。它们引导主语从句，并在句中作主语、宾语、表语、定语和状语等。
【即学即用】
在下列横线处填入适当的关系词
he said at the meeting astonished everybody present.
he said at the meeting encouraged everyone.
6. Thathe finished writing the composition in such a short time surprised us all.
* What,when 和wh-ever 等词有时也可不表示疑问。
Eg:→①what we should do next remains unknown.
我们下一步该干什么还不知道(what在句中作宾语，表示疑问）
→②What the lecturer said is of great value.
主讲人所讲的都非常有价值。（what 在从句中作宾语，表示陈述）
▼Wh-类连接副词或连接代词引导的主语从句可置于句首也可以置于句尾，置于句子句尾需要用形式主语it 代替wh-从句。
Eg:→①Who will come to teach us is unknown.谁来教我们还不知道。
→It is unknown that who will come to teach us.
→②When the new road is open to traffic has not been made clear.这条新路什么时候开通还不清楚。
→It has not been clear when the new road is open to traffic.
【小试牛刀】
一、把下列句子转化为it 作形式主语
（1）How the prisoner escaped remains a mystery.
It remains a mystery how the prisoner escaped.
（2）Why john did it this way was unexplained.
It was unexplained why john did it this way.
（3）When we will start off is an important question.
It is an important question when we will start off.
（4）Where I spend my summer vacation is really none of your business.
It is really none of your business when I spend my summer vacation.
▼注意事项
* 从句的语序：在任何情况下，主语从句都用陈述语序。
Eg ：Who did this is still unknown.这件事是谁做的还不知道。
What surprised me most was that the little girl could play the violin so well.
最令我感到惊讶的是，这个小女孩的小提琴拉得这么好。
* 主语从句作主语，主句谓语动词的单复数需根据从句表示的单复数意义决定
●what 引导的主语从句作主语
①单个的从句作主语时，谓语动词一般用单数形式。但what 和who 引导主语从句时，谓语动词的数应与作表语的名词保持一致。
Eg: What we need are more personal computers.我们需要的是更多的个人电脑。
What we need is more time.我们需要的是更多的时间。
●由其他词引导的主语从句，谓语动词用单数
Eg:Whether they will hod a party or not has not been decided.是否举行聚会还没有决定。
Who is responsible for the accidents is not clear.谁将为事故负责还不清楚。
●当同一个主语从句是由两个不同的引导词引导时，因为他表达的还是同一件事，所以，谓语动词一般用单数。
Eg:When and where we should hold the meeting has not been decided yet.什么时候在哪里举行会议还没有决定。
●当主语时由两个and 连接的主语从句组成，通常表示的是两件不同的事，主句谓语动词需用复数形式 Eg:What you eat and how much you exercise are important factors in a weight loss program.
在减肥计划中，你吃了什么和你做了多少运动是很重要的因素。
What caused the accident and who was responsible for it remain in a mystery to us.
什么造成了这起事故和谁将为其负责，对我们来说成了谜。
主语从句巧记口诀：整句作主语，其后单谓语。
莫忘加连词，that 不略但无义。
“是否”置前用whether, 其他应用靠翻译。
主语从句可后置，只需形式主语it 把它替。
【小试牛刀】
填入适当的谓语动词
a pair of rubber gloves and some plastic bags.
3.What she wanted from him just promises.
of great importance.
been decided.
【随堂练习】
一、在横线内填入适当的引导词
have taken it.
2. 3. the work can be completed on time is doubtful.
he was late..
6. of you comes first will receive a prize.
car you will choose to buy makes so difference.
二、完成句子（根据汉语提示及括号内的英语单词完成句子）
（据报道）some people stole others’money by ATM.(report)
(父母是否给他买一个新的MP3）Depends on his exam results.(buy)
3、 was not known at that time.(bag)
4、（大多数人需要的）is a comfortable and easy life.(need)
【易混淆单词】
一、How life began on earth is one of the biggest puzzles that scientists found hard to solve. 生命究竟是怎样起源的是科学家们觉得最难解决的问题之一。
*puzzle n.&v.
(1) n. 难题；难解之事；谜
be in a puzzle 不知如何是好
►搭配
be/feel puzzled about 对„„感到迷惑/迷惘的
●These computers are a puzzle to me. 我搞不懂这些电脑。
*辨析puzzle, question与problem
Eg:①This is quite a puzzle.那真是个令人费解的问题。
②Please answer my question.请回答我的问题。
③We can’t solve the maths problem.我们解不出这道数学题。
析：puzzle 指令人迷惑的、难以理解或回答的问题。
question 指主观提出的需要回答或解决的问题，通常作ask,answer 的宾语。
Problem 着重指难以解决（solve/settle)的“难题”或“问题”。
（2）vt. 迷惑；使伤脑筋，使困惑
►搭配puzzle out 思索出；琢磨出„„的答案
Eg:What he did puzzle me greatly.他的作为使我深感迷惑不解。
（3）vi. 苦思冥想；伤脑筋
►搭配puzzle about/over苦苦思索
I have been puzzling about this question for weeks.这个问题我冥思苦想好几个星期了。
Puzzlement n. 困惑
►拓展 puzzled adj. 困惑的；迷惑不解的（往往用于指人或人的表情、神色等）
Puzzling adj.令人困惑的；让人不解的（往往指物）
Eg: The puzzled look on his face suggested that he was puzzling over the puzzling problem.
【随即随练】
在下列横线处填入适当的词
’
二、They laid eggs too and existed on the earth for more than 140 million years.
它们也产卵，在地球上生存了1.4亿多年。
* lay v. (laid, laid)
(1)下（蛋）；产（卵）
Eg:①Turtles lay their eggs on the beach at night.海龟晚上在海滩上产卵。
②Are you hens laying well?你家的母鸡下蛋多吗？
（2）摊开；涂；敷
lay A on/over B 把A 涂/敷在B 上
►搭配
用A 把B 涂/敷起来
Eg:①The grapes were laid to dry on racks. 葡萄被摊放在架子上晾干。
②The floor was laid with newspaper.地板上铺了报纸。
(3)尤指轻轻地或小心地）放置；安放；搁
►搭配lay sb./sth.(down) on 把某人/某物放在„„上
Eg:①She laid the baby down gently on the road.她把婴儿轻轻地放在床上。
②He laid a hand on my arm.他把手搭在我的胳膊上。
lay sth.aside 把某物放在一边/搁置一旁
lay sth.down 放下，停止使用
► 拓展 贮备/贮存某物
lay sb.off 解雇某人
►辨析lie,lie 与lay
Eg:①You can lay the straw against the wall. 你可以把草靠墙放。
②How can you tell a lie to me? 你怎么能跟我撒谎呢？
③He lay there for two hours. 他在那里躺了两个小时。
④My school lies in the center of the city. 我的学校位于城市的中央。
【巧学活用】
选词填空：lie/lay
（1）There lay/lies an old temple in the north of the village.
（2）Mother laid the baby gently on the bed and left.
（3）He lied to his parents, which made them quite angry.
（4）He felt tired, so he went and lay down for a rest.
（5）Mom was busy preparing dinner, so she asked John to lay the table.
（6）The boy lying on the ground lied that he had laid the book on the desk.
三、These animals were different from all life forms in the past, because they gave birth to young baby animals and produced milk to feed them.
这些动物不同于过去所有的生命形式，因为它们产下幼崽并给幼崽哺乳。
* give birth to
(1) 生；分娩 （后接sb.)
Eg: Mary gave birth to a beautiful baby girl the day before yesterday.前天，玛丽生了一个漂亮的女婴。
(2) 孕育；使产生
Eg: It was the study of history that gave birth to social science.对历史的研究孕育了社会科学。
►①at birth 出生时 ②by birth 出身；在血统上 ③of no/good birth 出身低微/好的
►辨析give birth to与be born
Eg:① How many children did she give birth to? 她生了多少个孩子？
析：“生下，生产”的意思，其宾语是表示幼畜或婴儿的词语，其主语只能是表示雌性的词语；有时也作“使„„诞生”讲。
②No one knows when the girl was born.没人知道这个女孩是何时生的。
析：“出生”的意思，其主语通常只能是表示被生下来的人或动物。
例：The Chinese nation has Amany national heroes and revolutionary leaders.
A.given birth to B.give praise for C.given a reward to D.keep records of
【课后作业】
一、填入适当的关系词
2.. ’t make any difference.
holding a cellphone against your ear or storing it in your pocket may be harmful to your health.
5. was most important to her, she told me, was her family.
the delayed flight will take off depends much on the weather.
some people regard as a drawback is seen as a plus by many others.
one of you breaks the window will have to pay for it.
you said to me is like fresh air.
10.It is still a mystery she could survive under the ruins for 10 days.
二、翻译句子
1、我们何时举行运动会还没有决定。
When we shall hold our sports meeting is not decided.（It is not decided when we shall hold our sports meeting.)
2、他是如何成功的仍然是个谜。
How he was successful is still a puzzle.(It is still a puzzle how he was successful.)
3、他想要的是一本书。
What he wants is a book.,
4、很明显，他们急需援助。
That they badly need help is clear. (It’s clear that they badly need help.)
5、你没有看那部电影实在太遗憾了。
That you missed the film is a pity.(It’s a pity that you missed the film.)
6、他是否会参加会议都无关紧要。
Whether he will attend the meeting or not makes no difference. (It makes no difference whether he will attend the meeting or not.)
7、无论是谁最后一个离开，都应该关灯。
Whoever leaves the room last ought to turn off the lights.
8、他们什么时候坐飞机回来已经决定好了。
When they will come back by air has been decided.(It has been decided when they will come back by air.)