Unit18 Grammar The use of it[上学期]

课件41张PPT。It 用法一，作指示代词
二，作形式主语或形式宾语
It 指天气、时间、距离、自然现象、环境等。It is very cold today.
It is five o’clock.
It is twenty miles to the zoo.
It is very quiet here.
It is spring now.一，作指示代词1. it 可作指示代词代替上文提到的事情或情况。1.My pen is missing, I can’t find it anywhere.
2.Tom has failed in the exam.Have you heard about
it?2. 在性别不详或性别无关紧要时,亦可指动物,幼孩等。 They’ve got a baby and it is a ten-pounder.
Give the child whatever it wants.一，作指示代词3.用以代替指示代词this, that.(1)---What’s this? ---It’s a flag.
(2)---Whose exercise-book is that? ---It’s hers.4.起指示代词的作用,指心目中或上下文的一个人或事。 (1)---Who is knocking at the door ? ---It’s me.(指人)
(2) Sorry, I didn’t know it was you.
(3) I hate it when people talk with their mouths full.(指事)
(4) He is fifty but doesn’t look it.5. 指环境情况等.(1) It was very quiet at the moment.
(2) It was noisy last night.一，作指示代词6.指时间、天气、季节。(1)---What time is it? ---It’s eight o’clock.
(2)It was fine yesterday .
(3)It often rains in summer.7.指距离It is five kilometers from the office to my home.
It is a long way to the factory.一，作指示代词8. it 用法和which 引导的非限制性定语从句用法的区别。He failed in the exam,and it worried him.
He failed in the exam. It worried him.
He failed in the exam,which worried him.引导词先行代词it
常用于以下句式：形式主语it
It+ is/was+形容词/名词+不定式
It+ is/was+形容词/名词+ 动名词
It+ is/ was+形容词/名词+ that从句
在公共场所大声讲话是不礼貌的。
It is impolite to talk loudly in public places.
吃太多朱古力没什么好处。
It is no good eating too much chocolate.
很遗憾我没有早点想到这事。
It is a pity that I didn’t think of it earlier.上述句型中，后置的真正主语可取代 it而置于句首.
It is difficult to translate the article.
To translate the article is difficult.
It is strange that he didn’t come at all.
That he didn’t come at all is strange.

1. It is clear (obvious, true, possible, certain....) that ..... 该句型中it 是形式主语,真正的主语是that 引导的主语从句,常译为“清楚(显然，真的，肯定…)”　是主语从句最常见的一种结构。
It is very clear that he’s round and tall like a tree. 　　 = That he’s round and tall like a tree is very clear.
2. It is important (necessary, right, strange, natural...) that ... 该句型和上一个同属一个句型；由于主句中的形容词不同, that 后的从句中要用虚拟语气 (should + 动词原形)，should 可以省去, 建议记住该句型中的形容词。 It is important that we (should) learn English well. 　　 It is necessary that he (should) remember these words.
3. It is said (reported， learned....) that ... 译为“据说（据报道，据悉…)”。
It is said that he has come to Beijing. 　　 It is reported that another earth satellite has been put into orbit. 4. It is suggested ( ordered ... ) that ... 主句中的过去分词是表示请求，建议，命令等词时，that　后的从句要用虚拟语气(should + 动词原形), should 可以省；常译为＂据建议；有命令… 　　 It is suggested that the meeting ( should ) be put off. 　 It was ordered that we (should) arrive there in two hours. 5. It is a pity (a shame ...) that ... 该句型中, that后的从句一般用虚拟语气(should + 动词原形), should可省去.表示出乎意料,常译为“竟然” 。没有这种意义时,则不用虚拟语气.
It is a pity that such a thing ( should ) happen in your class. 这种事竟然发生在你们班上，真是遗憾！ 　 It is a pity that he is ill. 他生病了，真遗憾！6. It is time ( about time ，high time ) that ... 该句型中that 后的从句应该用虚拟语气,值得注意的是
① 常用过去时态表示虚拟．
② 有时也用should + 动词原形，should 不能省，常译为＂是（正是）…的时侯…＂ 　　 It is time that children should go to bed. 　　 = It is time that children went to bed.
7. It is the first ( second ... ) time that ...
该句型要和上一个句型区别开来,该句型中的 that 从句不用虚拟语气,而用完成时态。至于用什么完成时态,由主句的谓语动词的时态决定。如果是一般现在时,后面从句用现在完成时态;如果是一般过去时,后面从句则用过去完成时态,该结构中 that 可以省去;it有时用 this 替换.常译为＂是第一（二）…次…＂。 It is the first time I have been here. = This is the first time I have been here. 8. It is .... since ...。
该句型主要用作处理瞬间动词的完成时，又要和表示一段时间的时间状语连用的问题，主句中是时间作表语，其时态是现在时或完成时，since 引导的从句通常是一般过去时态，而且是瞬间动词。如果主句是一般过去时，从句则用过去完成时。It is ( has been ) 5 years since his father died.
9. It is ... when ...。 该句型中的 when 引导的是一个时间状语从句，主句中的 it 指时间，表语由具体的时间充当，常译为“当…的时候，是…”
It was 5 o’clock when he came here. 10. It be ... before ... 该句型主句中的 it 指时间， 主句中的时态常是将来一般时或过去时两种时态．主句中的表语多是long， not long ， 3 days ， 2 weeks 等表示时间段的词或短语，常译为＂…之后…＂。 It was 3 days before he went to Beijing. It will be not long before he finishes his job.
11. It happens (seems， looks， appears ) that... 该句型中it是形式主语，that 引导的是主语从句，主句中的happen ， seem等词是不及物动词。
It happened ( so happened ) that he met his teacher in the street. 碰巧… It seems that he will be back in a few days. 看来…12. It takes sb. ... to do sth. 该句型中的不定式是真正的主语，it是形式主语，句型中的直接宾语是时间，常译为＂做…要花费某人…＂。 　　 It took thousands of people many years to build the Great Wall.
13. It is no good (use ) doing sth. 该句型中的真正主语是动名词短语，主句中的表语可以是no good, ( not any good ), no use, ( not any use )。
It is no good learning English without speaking English.
14. It doesn’t matter whether ( if ) ... 该句型中whether (if) 引导的从句是真正主语，该句型常译为　“不论（是否）…没关系…。 　
It doesn’t matter if they are old. 15. It is kind (of sb.) to do sth. 该句型中的不定式短语是真正主语，如果不定式的逻辑主语是由 of引起，主句中的形容词必须是能表示逻辑主语特征的形容词。常见的有: bad, brave, careless, clever, cruel, foolish, good (好心的), honest, horrible, kind, lazy, modest, naughty, nice(有教养的), polite, rude, silly, stupid, wise, wrong (错误的)等。
这个句型可以改写为：sb. is kind to do sth. 。　 It is kind of you to say so. =You are kind to say so.
16. It is necessary (for sb.) to do sth. 该句型与上一个同属一个句型,如果不定式的逻辑主语是由for引起,主句中的形容词通常是表示重要性,紧迫性,频繁程度,难易,安全等情况的形容词。 常见的形容词有:① important, necessary, natural ② easy, safe, common, normal, hard, difficult, dangerous, unusual, rare, impossible, pleasant等。
It is important for her to come to the party. = It is important that she (should ) come to the party.17. It looks ( seems ) as if ... 该句型中it无意义, as if 引导一个状语从句。常译为,“看起来好象…”如果与事实不相符合，则用虚拟语气。 It looks as if he is ill.（真的病了）　 It looks as if he were ill. （没有生病） It seemed as if he were dying.
18. We think it important to learn a foreign language.
该句型中的it 作形式宾语,为了记忆方便我们可称该句型
为"6123结构"。
6指主句中常用的动词: think, believe, make, find, consider,
feel； 1指的是形式宾语it； 　 2指的是宾补的两种形式：形容词或名词； 3指的是真正宾语的三种形式：不定式短语,动名词短语或that引导的宾语从句。 We think it our duty to clean our classroom every day. 　 He felt it important learning English well. 　 They found it difficult that they would finish their work in two days.二，作形式主语或形式宾语1).it 作形式主语或形式宾语,代替不定式、动名词、
主语从句或宾语从句。It is interesting to listen to the popular music.
It is no use learning a theory without practice.
It is not yet known where she has gone.
I find it very easy to surf the internet.
I think it my duty to serve the people.
I think it necessary that students should master a foreign
language at school. It is interesting to listen to the popular music.
It is no use learning a theory without practice.
It is not yet known where she has gone.
I find it very easy to surf the internet.
I think it my duty to serve the people.
I think it necessary that students should master a foreign
language at school. It 作形式主语所构成的某些惯用句型。It doesn't matter…
It looks as if…
It seems that /as if…
It happened that…
It appears that…
It makes no difference…It looks as if it is going to snow.
It doesn't matter whether you will come or not.
It happened that I had seen the film.
It seems that he is learning Russian.
It+动词be+强调部分+who (whom) /that+其他部分
主语，宾语，表语或状语 强调的部分是人，that可以由who/whom换用。 it 用于强调句 Nancy saw your sister in Tokyo last week.
It was Nancy who/that saw your sister in Tokyo last week.
It was your sister whom/that Nancy saw in Tokyo last week.
It was in Tokyo that Nancy saw your sister last week.
It was last week that Nancy saw your sister in Tokyo.
怎样判断强调句型与其它从句 ？
It was in the park that she lost her necklace.
It is clear that not all boys like football.
可用恢复原句来判别，即是把It is/was… that…取消，如果 剩下的仍能组成一个完整的句子，这就是强调句，否则就不是。It is + 被强调部分 + that ...　 　 　 该句型是强调句型。将被强调的部分放在前面，其它部分置于that之后，被强调部分可以是主语，宾语，表语或状语，强调的主语如果是人，that可以由who换用。如果把这种句型结构划掉后，应该是一个完整无缺的句子；这也是判断强调句型与其它从句的方法。 　 It is time that children went to bed.
It is the first ( second ... ) time that ... 2. It is not until + 被强调部分 + that ... 该句型也是强调句型。主要用于强凋时间状语，译成汉语＂直到．．．才．．．＂，可以说是 not ... until ... 的强调形式。 It was not until she took off her dark glasses that I realized she was a famous film star. = Not until she took off her dark glasses did I realize she was a famous film star. 3. It is clear ( obvious， true， possible， certain....) that ..... 该句型中it 是形式主语，真正的主语是that 引导的主语从句，常译为＂清楚（显然，真的，肯定．．．）＂　是主语从句最常见的一种结构。 It was at the gate ___ he told me the news.
that B. what C. which D. when
2. Is ____ necessary to tell his father everything?
it B. that C. what D. he
3. Was it in this palace ___ the last emperor died?
that B. in which C. in where D. whichAAA4. Is ____ possible to fly to the moon in a spaceship?
now B. man C. that D. it
5. Was it during the Second World War __ he died?
A. that B. while C. in which D. then
AD6. Is ___necessary to complete the design before National Day?
this B. that C. it D. he
7. I don’t think ____ possible to master a foreign language without much memory work.
This B. that C. its D. it
8. Does ____matter if he can’t finish the job on time?
A. this B. that C. he D. itCDD9. It was not ____ she took off her dark glasses ____ I realized she was a famous film star.
when, that B. until, that
C. until, when D. when, then
10. Tom’s mother kept telling him that he should work harder, but ___ didn’t help.
he B. which C. she D. it
11. ____ is a fact that English is being accepted as an international language.
A. There B. This C. That D. It BDD12. How long ____to finish the work?
A. you’ll take B. will take you
C. you’ll take it D. will it take you
13. It was through Jack ____ Mary got to know Bob.
A. who B. whom C. how D. that
14.It was simply for that reason ____ I wouldn’t tell him the truth.
A. why B that C. which D. so15.I think ______ right that you didn’t go there.
A. you B. that C. it D. its
16.______ is no good ______ without doing anything.
A. This; talking B. It ;to talk
C. It; talking D. That; to talk
17. It ______ Mike and Mary who helped the old man several days ago.
A. was B. are C. were D. had been
18. ______ four years since I left my home town.
A. It was B. There was C. There is D. It is 19.People in the west make ______ a rule to buy Christmas presents for their relatives and friends.
A. that B. it C. this D. as
20.______ needs further discussion whether we’ll build a library or not.
A. That B. This C. It D. The thing
21.We found ______ impossible to get rid of the nuclear waste.
A. that B. this C. / D. it22.There is a photo on the wall. _____a photo of Lei Feng.
A. It B. It’s C. Its D. He’s
23.His father kept telling him that he should work harder ,but ______ didn’t help.
A. it B. he C. which D. she
24 .He felt ______ to work for human rights and progress.
A. it his duty B. his duty
C. that is a duty D. that is his duty 25.Let’s get through the work quickly._____ seems to be little time left now.
A. It B. There C. That D. Here
26. _____ is different between A and B.
A. There B. It C. Where D. What
9.______ is no difference between A and B.
There B. Where C. It D. What
27.He said,“______ a long way to school._____ a long way to go
yet before we arrive.”
A. It is; There is B. There is ; It is
C. It is; It is D. There is ; There isLanguage study:Nouns:1.The jungles of South East Asia are the natural
habitat to many different kinds of subtropical
animals and plants.2.Canada is covered by very large forests.3.Inner Mongolia is famous for its grasslands.4.Some of the mountains in Southwest China belong
to the highest in the world.5.The Summer Palace is built on the hills to the west
of Beijing.6.Sand from the deserts in Northwest China is
carried over hundreds of kilometres and causes
terrible sand storms in spring.Adjectives:1.By the end of spring, our schoolyard has turned
into a grassy field.2.The best swimming and sunbathing is along the
sandy beaches on Hainan Island.3.The river flows through flat land between the
mountains.4.Most of the countryside in Southeast England is
hilly.5.There is only a rocky path that leads to the top of
the mountain.6.In the past the hillsides and most of the land was
wooded.7.Coming from a mountainous country , the girl
likes climbing mountains very much.Combinations:
1.The USA is famous for the Rocky Mountains.
2.The mountainous jungles of Central and South
America are among the most dangerous areas
for tourists.
3.Where once green forests could be seen, there are
now only sandy hills.
4.Many young travellers choose a hiking trip on the
wooded hills and mountains on the South Island.
5.Over a period of millions of years, high mountains
are turned to hilly, and finally into flat lands.
6.Sheep farming is found everywhere on the grassy
hills in the east.GrammarAnswers to Exercises 1:1.It is very exciting to receive a letter from a
foreign friend.
2.It is not a good habit to eat too much junk
food
3.It is dangerous to drive too fast.
4.It is bad manners to talk with your mouth full
5.It is a pleasure to see you again.
6.It has always been fer dream to study abroad.Answers to Exercises 2:1.It is strange that you don’t know where
New Zealand is.
2.It is wonderful that they are going to invite
me to dinner.
3.It was not surprising that he failed his
maths exam.
4.It was a shock to all that his secretary stole
the money.Answers to Exercises 3:1.It is always sunny in Hainan.
2.It takes about 20 minutes to get to the airport.
3.It is the third of April today.
4.It is a good idea to bring something to eat on
the train.The end