it用法总结(高三总复习).ppt

一、一、it 作人称代词的用法作人称代词的用法1.指事物指事物作为人称代词，作为人称代词，it 可以可以除人以外除人以外的一切事的一切事物或动物。如：物或动物。如：I dropped my watch and it broke.我我把手表掉在地上摔坏了。把手表掉在地上摔坏了。Its hard work,but I enjoy it.工作很工作很辛苦，可是我乐意干。辛苦，可是我乐意干。“Where is the dog?”“Its in the bedroom.”“狗在哪狗在哪?”“在卧室里在卧室里”。2.指人指人it 指人主要用于指指人主要用于指不性别不明的婴儿不性别不明的婴儿或用或用于确认某人的身份。如于确认某人的身份。如：Is it a boy or a girl?是男孩还是女孩是男孩还是女孩?There is a knock on the door.It must be the postman.有人在敲门，一定是邮递员。有人在敲门，一定是邮递员。【说明说明】在答语中，常用来指本人，如说在答语中，常用来指本人，如说Its me。3.代替某些代词代替某些代词代词it 还可用于代替指示代词this,that 以及复合不定代词 something,anything,nothing等。如等。如：“Whats this?”“Its a new machine.”“这是什么这是什么?”“是一种新机器是一种新机器”。Nothing is wrong,is it?没出什么问题，没出什么问题，是吗是吗?二、二、it 作非人称代词的用法作非人称代词的用法1.1.基本用法基本用法基本用法基本用法it it 作非人称代词的用法，主要用于指时间、距离、作非人称代词的用法，主要用于指时间、距离、作非人称代词的用法，主要用于指时间、距离、作非人称代词的用法，主要用于指时间、距离、价值、天气、气候及温度等自然现象。价值、天气、气候及温度等自然现象。价值、天气、气候及温度等自然现象。价值、天气、气候及温度等自然现象。1.1.ItIt is Friday today.is Friday today.2.2.ItIt was very cold last Monday.was very cold last Monday.3.3.ItIt is about 8:30 now.is about 8:30 now.4.4.ItIt is about 25km from Linquan to Fuyang.is about 25km from Linquan to Fuyang.5.5.ItIt lies in the south of Anhui.lies in the south of Anhui.6.6.ItIt is 40C!You got a high fever!is 40C!You got a high fever!dateweathertimedistanceplacetemperature 2.2.2.2.用于某些句型用于某些句型用于某些句型用于某些句型It It s time for sth.s time for sth.该做某事了。该做某事了。It It s time to do sth.s time to do sth.该做某事的时候了。该做某事的时候了。It It s time for sb to do sth.s time for sb to do sth.某人该干某事了。某人该干某事了。It It s(about/high)time+that-s(about/high)time+that-从句从句.某人该做某事了。某人该做某事了。(从句谓语用过去式，有时也用从句谓语用过去式，有时也用“should+should+动词原形动词原形”)It It s first(second)time+that-s first(second)time+that-从句从句.某人第几次干某事。某人第几次干某事。(从句谓语用现在完成时从句谓语用现在完成时)It It s+s+时间段时间段 +since.+since.自从自从有一段时间了。有一段时间了。It It s+s+时间段时间段 +before.+before.过多长的时间才过多长的时间才 it it s=it wass=it wasIt It s+s+时间段时间段 +that.+that.多久了多久了Its+Its+时间段时间段+when.+when.是在某个时刻是在某个时刻 It is time for breakfast.It is time to have breakfast.It is time for us to have breakfast.It is the first time Ive been here.It is two weeks since I saw him Its ten years before I graduated.Its ten years that Ive lived here for It was ten years ago when I graduated 三、三、it用作形式主语用作形式主语1.1.1.1.基本用法基本用法基本用法基本用法当不定式、动名词、从句等复杂成分用作句子主当不定式、动名词、从句等复杂成分用作句子主语时，为保持句子平衡，通常把真正的主语放在语时，为保持句子平衡，通常把真正的主语放在句末，而在句首使用形式主语句末，而在句首使用形式主语itit。如：如：Its very important to remember this.s very important to remember this.记住这记住这一点很重要。一点很重要。Its hard work climbing mountains.s hard work climbing mountains.爬山是费劲爬山是费劲的事。的事。Its unknown when he will come.s unknown when he will come.他什么时候来他什么时候来还不知道。还不知道。2.2.2.2.用作形式主语的的重要句型用作形式主语的的重要句型用作形式主语的的重要句型用作形式主语的的重要句型(1)it(1)it 作形式主语替代不定式作形式主语替代不定式作形式主语替代不定式作形式主语替代不定式 构成构成”It+be+adj.for(of)sb to do sth“It+be+adj.for(of)sb to do sth“某人做某某人做某某人做某某人做某事事事事 It is hard for him to make up his mind.is hard for him to make up his mind.他很难下他很难下定决心。定决心。It was foolish of her to say such a thing.was foolish of her to say such a thing.她说那她说那样的话，真是太蠢了。样的话，真是太蠢了。【TipTip】介词介词 of of 与与 for for 的区别是：的区别是：of of 用于指某人的性格、属性、特征等，介词用于指某人的性格、属性、特征等，介词forfor表示对象，意为表示对象，意为“对对来说来说”2)It is V-ed+that 2)It is V-ed+that It is said(reported,learned)+that It is said(reported,learned)+thatIt is said that he has come to Beijing.It is said that he has come to Beijing.It is suggested(ordered,demanded,It is suggested(ordered,demanded,insisted,commanded)+that insisted,commanded)+that 从句中的过去分词是表示请求，建议，命令等词从句中的过去分词是表示请求，建议，命令等词时，时，thatthat后的从句要用虚拟语气后的从句要用虚拟语气(should+V(should+V原形原形).Should).Should可以省略。译为可以省略。译为“据建议；有命令据建议；有命令”It is suggested that the meeting(should)be put It is suggested that the meeting(should)be put off.off.3)It is a pity(a shame)that3)It is a pity(a shame)that That That 后的从句一般用虚拟语气后的从句一般用虚拟语气 (should+V(should+V原形原形原形原形),),should should 可以省略可以省略.表示出乎意料，译为表示出乎意料，译为”竟然竟然“。没有这种意义时，则不用虚拟语气。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 It is a pity that such a thing(should)happen in your class.your class.(4)It takes sb.+(4)It takes sb.+时间段时间段时间段时间段 +to do sth.+to do sth.某人某人某人某人做某事花了做某事花了做某事花了做某事花了时间时间时间时间It takes years to takes years to master a new language.master a new language.要要花多年的时间才能掌握一门新的语言。花多年的时间才能掌握一门新的语言。【TipTip】此句型可以有以下多变种变体：此句型可以有以下多变种变体：It took me an hour to write the letter.took me an hour to write the letter.=The letter took me an hour(to write).=The letter took me an hour(to write).=I took an hour to write the letter.=I took an hour to write the letter.(5)It is up to sb to do sth.(5)It is up to sb to do sth.该由某人做某事该由某人做某事该由某人做某事该由某人做某事Its up to you to to make the choice.Its up to you to to make the choice.得由你来得由你来作选择。作选择。(6)it look(seem,appear,happen,occur)that(6)it look(seem,appear,happen,occur)that as ifas if似乎似乎似乎似乎It seemed as though he didnt recognize me.It seemed as though he didnt recognize me.他似乎没认出我来。他似乎没认出我来。It happened that I was out when he called.It happened that I was out when he called.他他打电话时我碰巧不在家。打电话时我碰巧不在家。(7)If it were not for/If it hadnt been(7)If it were not for/If it hadnt been forfor若不是因为若不是因为若不是因为若不是因为If it were not for their help,we couldnt have If it were not for their help,we couldnt have got over the difficulties.got over the difficulties.要不是他们帮助，这要不是他们帮助，这些困难我们不克服不了的。些困难我们不克服不了的。四、四、it用作形式宾语用作形式宾语1.1.基本用法基本用法基本用法基本用法当不定式、动名词、从句等复杂成分用作宾语且当不定式、动名词、从句等复杂成分用作宾语且其后跟有宾语补足语时，通常会在宾语补足语前其后跟有宾语补足语时，通常会在宾语补足语前使用形式宾语，而将真正的宾语移至句末。使用形式宾语，而将真正的宾语移至句末。其基本结构为其基本结构为“动词动词动词动词+it+it+it+it+宾语补足语宾语补足语宾语补足语宾语补足语+不定式不定式不定式不定式(动动动动名词或从句名词或从句名词或从句名词或从句)”。如：如：I find I find it difficult to do the job well.difficult to do the job well.我发现做我发现做好这件事不容易。好这件事不容易。I think I think it best that you should stay here.best that you should stay here.我认我认为你最好住这儿。为你最好住这儿。We think We think it no use complaining.no use complaining.我们认为抱怨我们认为抱怨是没有用的。是没有用的。2.2.用作形式宾语的几个特殊结构用作形式宾语的几个特殊结构用作形式宾语的几个特殊结构用作形式宾语的几个特殊结构(1)(1)动词动词动词动词+it+that-+it+that-从句。从句。从句。从句。如：如：I like I like it that you came.that you came.你来了，我很高兴。你来了，我很高兴。I take I take it(that)he will come on time.(that)he will come on time.我认为他我认为他会准时来的。会准时来的。You can put You can put it that it was arranged before.that it was arranged before.你你可以说这是以前安排的。可以说这是以前安排的。Rumor has Rumor has it that the defence minister will that the defence minister will soon resign.soon resign.据传闻，国防部长不久就要辞职。据传闻，国防部长不久就要辞职。【说明说明说明说明】能用于此结构的动词不多，常见的有能用于此结构的动词不多，常见的有 have,take,put,like have,take,put,like 等。等。(2)(2)动词动词动词动词 +it+when(if)-+it+when(if)-从句。从句。从句。从句。如：如：如：如：I dislike I dislike it when you whistle.when you whistle.我不爱听你吹口哨。我不爱听你吹口哨。We really appreciate it when she offered to We really appreciate it when she offered to help.help.她来帮忙了，我们十分感激。她来帮忙了，我们十分感激。Id prefer it if I didnt have to do so much Id prefer it if I didnt have to do so much work.work.要是我不必做那么多工作，好就太好了。要是我不必做那么多工作，好就太好了。【说明说明说明说明】能用于此结构的动词不多，常见的有能用于此结构的动词不多，常见的有 enjoy,enjoy,hate,love,like,dislike,appreciate,prefer hate,love,like,dislike,appreciate,prefer 等。等。(3)(3)动词动词动词动词 +prep+it+that-+prep+it+that-从句。从句。从句。从句。如：如：See to See to it that youre not late again.that youre not late again.注意千万注意千万不要再迟到。不要再迟到。Look to Look to it that this doesnt happen again.that this doesnt happen again.注意注意不要再发生这种事。不要再发生这种事。You may rely on You may rely on it that hell come to meet you.that hell come to meet you.你放心，他会来接你的。你放心，他会来接你的。I cant answer for I cant answer for it that he will come.that he will come.我不能我不能保证他会来。保证他会来。【说明说明】能用于此结构的动词不多，常见的有能用于此结构的动词不多，常见的有see see to,look to,insist on,stick to,depend on,to,look to,insist on,stick to,depend on,answer for answer for 等。等。(4)(4)动词动词动词动词 +it+it+介词短语介词短语介词短语介词短语+that-+that-从句。从句。从句。从句。如：I owe it to you that I am still alive.多亏有你我才仍然活着。I took it for granted that he would help us.我认为他会帮助我们的。【说明说明】能用于此结构的动词不多，常见的有take it for granted,bring it to sbs attention,owe it to sb 等。五、用于强调句型中五、用于强调句型中1)It+be+被强调部分被强调部分+that/who(a person)从句从句I met Tom in the park yesterday.1)It was I who met Tom in the park yesterday.2)It was Tom who I met in the park yesterday.3)It was in the park that I met Tom yesterday.4)It was yesterday that I met Tom in the park.2)It is not until+被强调的部分被强调的部分+that 该句型也是强调句型，主要用于强调时间状语，该句型也是强调句型，主要用于强调时间状语，该句型也是强调句型，主要用于强调时间状语，该句型也是强调句型，主要用于强调时间状语，译成译成译成译成“直到直到直到直到 才才才才”，可以说是，可以说是，可以说是，可以说是not untilnot until 的强的强的强的强调形式。调形式。调形式。调形式。ItIt was not until she took off her dark glasses was not until she took off her dark glasses that I realized she was a famous film star.that I realized she was a famous film star.=Not until she took off her dark classes did=Not until she took off her dark classes did I realize she was a famous film star.I realize she was a famous film star.=I didnt realize she was a famous film star=I didnt realize she was a famous film star until she took off her dark glasses.until she took off her dark glasses.六、六、it 常用的固定搭配常用的固定搭配1.1.make itmake it1)1)在口语当中相当于在口语当中相当于在口语当中相当于在口语当中相当于succeedsucceed,表示表示表示表示:成功、做到、成功、做到、成功、做到、成功、做到、说定、赶上、及时到达说定、赶上、及时到达说定、赶上、及时到达说定、赶上、及时到达 如如如如:Its hard to make Its hard to make it to the top in show to the top in show business.business.2 2)在口语中相当于在口语中相当于在口语中相当于在口语中相当于fix the date forfix the date for,表示表示表示表示“约定约定约定约定好时间好时间好时间好时间”如如如如:Shall we meet next weekShall we meet next week?OK.We just make OK.We just make it next Saturday.next Saturday.2.take it/things easy 2.take it/things easy 相当于相当于相当于相当于DonDon t worry.t worry.用来劝告别人用来劝告别人用来劝告别人用来劝告别人,表示表示表示表示“不要慌不要慌不要慌不要慌,别担心别担心别担心别担心,”,”Take it easyTake it easy！He will do He will do it well.well.3.It all depends/that all depends3.It all depends/that all depends 在口语中在口语中在口语中在口语中,相当于相当于相当于相当于it hasnt been decided yetit hasnt been decided yet,表示表示表示表示“那那那那得看情况得看情况得看情况得看情况,还没有定下来还没有定下来还没有定下来还没有定下来”Are you going to the countryside for Are you going to the countryside for holidayholiday?It/That all depends./That all depends.4.Its up to sb.在口语中在口语中,相当于相当于its decided by sb.表示表示“由由决定决定,由由负责负责,取决于取决于”Shall we go out for dinner？Its up to you.Its time后的从句用后的从句用 虚拟语气虚拟语气一、基本用法一、基本用法一、基本用法一、基本用法从句谓语通常用从句谓语通常用从句谓语通常用从句谓语通常用过去式过去式过去式过去式表示现在或将来，有时也表示现在或将来，有时也表示现在或将来，有时也表示现在或将来，有时也用过去进行时或用过去进行时或用过去进行时或用过去进行时或“should+should+动词原形动词原形动词原形动词原形”(should(should不不不不能省略能省略能省略能省略)，其意为，其意为，其意为，其意为“(早早早早)该干某事了该干某事了该干某事了该干某事了”：I thinkI think It It s times time you went to bed.you went to bed.我想你该睡觉了。我想你该睡觉了。It It s times time we went were going,should go.we went were going,should go.我们该走了。我们该走了。I I m getting tired.m getting tired.It It s times time we went home.we went home.我累了，我我累了，我们该回家了。们该回家了。I think I think it it s times time they were taught a lesson.they were taught a lesson.我想现在该我想现在该给他们一点教训了。给他们一点教训了。It It s times time you looked ahead and made plans for your you looked ahead and made plans for your retirement.retirement.是你为以后想一想并对退休后的生活是你为以后想一想并对退休后的生活做出安排的时候了。做出安排的时候了。二、同义表达二、同义表达该是孩子们上床的时间了。Its timethe kids were in bed.=Its timefor the kids to be in bed.It is time that the children went to bed.=It is high time that the children should go to bed.三、两点说明三、两点说明三、两点说明三、两点说明(1)(1)timetime前有时有前有时有aboutabout和和和和highhigh修饰：修饰：It It s high time we left.s high time we left.我们早该动身了。我们早该动身了。It It s high time you bought a new car.s high time you bought a new car.你该买辆新车了。你该买辆新车了。I think itI think it s high time that she made up her mind.s high time that she made up her mind.我想我想她该拿定主意了。她该拿定主意了。It It s high time they began to take you seriously.s high time they began to take you seriously.现在他现在他们应该开始认真对待你了。们应该开始认真对待你了。(2)(2)与其他的虚拟结构不同，该结构与其他的虚拟结构不同，该结构不能不能不能不能在该用在该用 waswas 时而用时而用 werewere：It It s time I was in bed.s time I was in bed.我该上床睡了。我该上床睡了。(不用不用were)were)