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1、It的用法,Discover “it”,It rains heavily. It is 20 kilometers from granddads house to James. It is November 11, 2005. It is 9 oclock. It will be lovely in the garden night. It is bad to smoke. It is he that called me yesterday. I think it important that you should attend the meeting.,天气,距离,日期,时间,环境,形式主语
2、,强调句型,形式宾语,a.用作人称代词，代替前文提到过的事物，以避免重复: Throw wasted paper in the dustbin. It is just beside you. b.还可以指代前面整件事情： This spade（铁锹）is made of iron. It is known to all.,人称代词,在回答含指示代词thisthat的问句时，常用it指代 - Who is that? - It is Lucy. - Whats that on the right? - I guess it might be a watermelon. 电话中的对话, 不能用it
3、代替this “Hello! Who is that (speaking)?” “This is john (speaking).,指示代词,日期，距离，价值，度量，温度，环境等,指代性别不详的婴幼儿,他她是谁？,Who is it?,指代说话者心目中不太清楚的那个人,-Who is knocking at the door? -Its may be Tom.,The baby is crying. It might be hungry.,it指代上文提到的单数可数名词或不可数名词， 即“同类又同物” one表示“同类不同物”, 只能代替可数名词单数，相当于a/an+可数名词单数；还可以指众多
4、中的一个 （复数名词用ones指代) that表示“同类不同物”，只在平级结构或比较级结构或表对比结构中指代前文出现的可数名词单数或不可数名词。（复数名词用those指代）,it, one, that 区别,易误辨析:,I had a good pen, but I lost it yesterday. Ill buy one tomorrow.,同类又同物,同类不同物,Im moving to the countryside because the air there is much fresher than that in the city.,同类不同物,易误辨析:,1.- Would y
5、ou like to buy a bicycle of this kind? - Yes, Id like to have _. A. it B.that C.one D.this 2.The color of my coat is different from _ of yours. A. it B. one C. that D. this 3.The machines we use today are much better than _ we use ten years ago. A. it B.that C.one D.those 4.These shoes are too tight
6、,do you have large_? A. it B.that C.ones D.one,Exercise,当主语由动词不定式（短语），动名词（短语）或主语从句充当时，为避免头重脚轻，使整个句子平衡，常把这些主语放在句末，而把it放在句首充当形式主语。,形式主语,to do,doing,be n.,be done,It,be adj.,主语从句,形式主语,真正主语,v.,it代替不定式,It be adj. of sb. to do It be adj./ n. for sb. to do,形式主语,当形容词表示不定式逻辑主语 sb. 的性质时，用of 其他的形容词用for,Sentenc
7、e patterns:,eg: It is kind of you to help me. It is important for us to learn English well. It is a pity for you to miss the concert.,it代替动名词,形式主语,Sentence patterns:,It is +adj./ n. + doing,当形容词或名词为useless/no use/no good/no point，后面必须跟动名词,eg: It is no good smoking. It is no use trying again. It is u
8、seless arguing with him,it代替从句,形式主语,Sentence patterns:,be n.,be done,It,be adj.,v.,主语从句,主语从句,be n.,be done,be adj.,v.,It is clear ( obvious, true, certain.) that . It is very clear that hes round and tall like a tree. = That hes round and tall like a tree is very clear. It is obvious that going for
9、sports will do a lot of good to your health.,It is important ( necessary, strange, natural.) that . that 从句中要用虚拟语气（should）+ 动词原形 It is important that we (should) learn English well. It is necessary that he (should) remember these words.,常见句型,It is said (reported, learned.) that . 该结构常译为据说（据报道，据悉） It
10、 is said that he has come to Beijing. It is reported that another earth satellite has been put into orbit.,It is suggested (demanded/commanded.) that . 当主句中的过去分词表示请求，建议，命令时，that从句要用(should) + do；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
11、there in two hours.,常见句型,It happens (seems，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 that he met his teacher in the street. It seems that he will be back in a few days.,It looks ( seems ) as if . 该句型中it无意义， as if 引导一个表语从句。 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
12、 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.,常见句型,It is a pity ( a shame . ) that . 该句型中，that后的从句一般用（should）+ do，表示出乎意料，常译为竟然。 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！,It is time
13、 ( 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 常用过去时态表示虚拟 有时也用should + do，should 不能省，常译为该到做的时侯了 It is time that children should go to bed. = It is time that children went to bed.,常见句型,1. 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。如果主句是一般现在时，后面从句
14、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“这是某人第.次做某事 It is the first time I have been here. = This is the first time I have been here.,2. It is up to sb. to do sth 应由某人做某事。 It is up to you to decide whether we start or not.,“It be + n +主语从句”的特殊句式结构,3. It is + 一段时间 + since .。 sinc
15、e 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 be + n +主语从句”的特殊句式结构,It is 5 years since his father died. 他的父亲已经死了五年了 It is five months since I arrived in New York. 我到纽约已经五个月了。 It is five months since I was in New York. 我离开纽约已经五个月了。,（注意：终止性动词表示从动作发生时算起；如果是状态动词或持续性动词，则从动作或状态结束时算起。）,4. It is + 时间点
16、+ when .。 该句型中的 when 引导的是一个时间状语从句，主句中的 it 指时间点，表语由具体的时间充当，常译为当的时候，是 It was 5 oclock when he came here. 5. It was will be + 一段时间 + before +从句 该句型主句中的 it 指时间段，主句中的时态常是一般将来时或一般过去时，主句中的表语多是long，3 days，2 weeks等表示时间段的词或短语 It was 3 days before he went to Beijing. It will not be long before he finishes his
17、job.,“It be + n +主语从句”的特殊句式结构,It will be several years before we meet again. 我们要过好几年才能再见面。 It will not be long before they set out for the front. 用不了多久他们就会出发去前线。,It will be + 时间段 + before + 从句 “要过才” It will not be + 时间段 + before + 从句 “用不了就”,It was two hours before the fireman arrived here. It was no
18、t five minutes before the fireman arrived here.,两个小时之后消防员才到.,没过五分钟消防员就到了.,It was + 时间段 + before “之后才” It was not + 时间段 + before “没过就”,1.Its years _ (since, before, after, that) I painted this beautiful picture. 2.It will be years _ (since, before, after, that) I paint this beautiful picture. 3.It wa
19、s years _ (since, before, after, that) I painted this beautiful picture.,表示从since从句谓语动作发生以后到现在所经过的一段时间，译为“自从.以来已多久了”,It is +时间段+since(过去时).,It + will be +时间段 +before(一般现在时),表示从现在起到before从句谓语动作发生所经过的一段时间,译为“多长时间后才会/就会做”,It + was + 时间段 + before(过去时),表示从过去某一时间到before从句谓语动作发生所经过的一段时间,译为“之后才/就做了”,易误辨析:,T
20、ranslate : 过了很久他才回来. 2. 我们很久后才会见面的. 3. 我离开这所学校已经很久了.,It was long before he came back.,It will be long before we meet again.,It is long since I left this school.,It is + 时间段+since(过去时),It + will be+ 时间段+ before(一般现在时),It + was + 时间段+ before(过去时),易误辨析:,Sb + V + it + adj. + ( for sb. ) to do sth.,The c
21、hairman thought _ necessary to invite Professor Smith to speak at the meeting.(05全国) A. that B. it C. this D. him,Sentence patterns:,B,形式宾语,makebelievefeel findconsiderthink,hardpossibleimportant clearnecessary,宾语从句,我们认为你什么时候出发并不重要。,We consider it unimportant when you set off.,Translation,He made it
22、 quite clear that he wouldnt change his mind,他明确表示不会改变他的主意,S+ V + it + n + ( for sb. ) to do sth. 宾语从句,S + V + it + no + n + doing sth. ( need 除外）,形式宾语,I think it his duty to clean the blackboard.,Sentence patterns:,no usegoodpointharm,1. 作为医生，我们觉得救死扶伤是我们的职责。 2. 他们相信适当锻炼身体毫无坏处。,1. As doctors, we fee
23、l it our duty to save the dying and treat the wound.,2. They believe it no harm doing the exercise appropriately.,Translation,I like _ in the autumn when the weather is clear and bright.(04全国) A. this B. that C. it D. one,点拨:这是it作形式宾语的一种特殊用法.少数动词(如like,love,enjoy,dislike,hate,dont mind, appreciate,f
24、eel like等)或包含介词的动词短语 (如see to,depend on,be fond of等)后接宾语从句,必须先由it担任形式宾语,再接从句.,I like (enjoy, hate) it when I would appreciate it if see to (depend on) it that,Sentence patterns:,C,形式宾语,点拨: 这也是it作形式宾语的一种特殊用法. 少数动词短语中包含it作形式宾语,其结构为： sb owe it to sb+ 连词 + clause 把归功于 bring it to sb+ 连词 + clause 把带给某人 l
25、eave it to sb + 连词 + clause 把留给某人去做 take it for granted + 连词 + clause 某人想当然 keep in mind + 连词 + clause 牢记,形式宾语,She took _ for granted that he was liked by all the people. A. this B. that C. it D. one,C,1. You can leave the problem to me if you are busy. 2. Please keep in mind that you are a Chinese
26、man.,Translation,如果你忙的话，你可以把这个难题留给我。 请你记住你是一个中国人。,形式宾语,sb v + it adj./ n. (for sb) to do / 宾语从句,sb v + it no n. (usegood.) doing (除了need),sb appreciate + it + 宾语从句,sb leave it to sb + 宾语从句 sb owe it to sb + 宾语从句 sb bring it to sb + 宾语从句 sb take it for granted + 宾语从句 sb keep in mind + 宾语从句,It常可代替不定式（
27、短语）、动名词（短语）或从句在句中作形式宾语，而将真正的宾语放在句子后面。为方便记忆，我们可将it 作形式宾语的句型称为“6123结构“。,指主句中常用的动词：think， believe， make， find, consider， feel； 指的是形式宾语it； 指的是宾补的两种形式：形容词或名词； 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。,形式宾语,1. -There is still a copy of the book in the library. Will you go and borrow ? -No, Id rather buy in t
28、he bookstore. 2007 陕西卷 A. it;one B. one;one C. one;it D. it;it 2. Little joy can equal _ of a surprising ending when you read stories. 2007 四川卷 A. that B. those C. any D. Some 3. He didnt make _ clear when and where the meeting would be held.2007 天津卷 A. this B. that C. it D. these,4. （2011福建21） We h
29、ave various summer camps for your holidays. You can choose _ based on your own interests. A. either B. each C. one D. it 5. （2010全国II 14）The doctor thought _ would be good for you to have a holiday. A. this B. that C. one D. it 6. （2010陕西卷12）The cost of renting a house in central Xian is higher than _ in any other area of the city. A. that B. this C. it D. one 7. (2011天津1) We feel _ our duty to make our country a better place. A. it B. this C. that D. one,Summary,it作人称代词，代替前面提到的事物 it作指示代词，指代this或that it指代不明身份的人或不明性别的婴儿 it指代时间，日期，距离，自然现象等 it作形式主语 it作形式宾语 “6123” 结构,Thank you,