It+be+时间+从句.docx

It+be+时间+从句 归纳1. It is/has been+时间段+since+一般过去时自从.以来已有.久了例1：It is/has been 10 years since he came here.这类句型可转化为：=Ten years has passed since he came here.这一句型可扩展为：It was+时间段+since(从句用过去完成时)例2：It was years since he had arrived in China.(过去时+since+过去完成时)He said it was two years since he had joined the army.他说他当兵已有两年了。需要注意的是since从句的谓语动词一般是非延续性动词，但有时也可用延续性动词或表示状态的词，此时需要注意句子的翻译（瞬顺延反）：例3：It is three years since she came to our class.她来我们班已经有三年了。It is three years since she was in our class.她离开我们班已经有三年了。It is half a year since he was ill. 他病愈有半年了。It is half a year since he smoked.他戒烟有半年了。2. It+was+时间点+when (从句用一般过去时) 某事发生在什么时间It will be+时间点+when (从句用一般现在时表将来)it指时间，点时间前没有介词，when引导的从句是时间状语从句。例1：It was already 8 oclock when he came back.当他回家时已经8点了。例2：It will be midday when they get home.当他们到家时将是中午。3. It+will(not) be +时间段+before+现在时It was(not)+时间段+before+过去时肯定形式表示过.时间才.”，否定形式表示没有过.就.例1：It will be another year before he comes here.例2：It was not long before he came home.不久他就回来了It was some time _ we realized the truth.A.whenB.untilC.sinceD.before正确答案：D。过了一段时间后我们才了解了真相。4. It/This is+the+序数词+时间+定语从句(从句用现在完成时) 这是第一/二/三次做某事了，其中that 可省略，例1：It is the first time (that) I have been here.(定语从句)该句型可扩展为：It was+序数词+时间+定语从句(从句用过去完成时)例2：It was the second time he had been out with her alone.例3：Its the second time you_late this week.A.arriveB.arrivedC.have arrivedD.had arrived正确答案：C。这是这个星期你第二次迟到了。5. It is+(high) time+that+did(虚拟语气)从句也可用should+V(原形)该做的时候了,引导词that常省去， 从句谓语动词常用过去时态，或should+V.但其含义并非指过去，而是指现在或将来.例1：It is (high) time (that) we stopped pollution.例2：It is (high) time (that) you came/should comehere.写作中表示建议时也常可用这类句型。例3：Its high time we took measures to solve thisproblem.6. It be+时间(被强调部分)+that在某一时间发生了某事例1：It was at 6 oclock that we heard the noise.例2：It was 3 years ago that he joined the army.最简单的判断方法是：当表示时间的词前有介词或者后有副词时，一定是强调结构，必用that。试比较下面句式与强调句的不同之处：It was already ten oclock when he arrived.It is ten years since I met you last.It was quite some time before he found the elephant.以上几句中时间前无介词后没副词故不是强调句型。类似的题目1. It was about 600 years ago _the first clock with a face and an hour hand was made.A. when B. before C. that D. since正确答案：C。2. -Did Jack come back early last night ? -Yes .It was not yet eight oclock _ he arrived home .A. before B. when C. that D. until 正确答案：B他回家时还不到8点。3. He was told that it would be at least three more months _ he could recover and return to work.A. when B. before C. since D. that正确答案：B。“多长时间以后某事才发生”。4 .-What was the party like ?-Wonderful. It is years _I enjoyed myself so much. A. after B. before C. when D. since 正确答案：D。我很久都没玩得这么开心了。before long 与long before记忆诀窍和用法介绍记忆诀窍: long 在前很久前 long在后不久后 用法：long before单独使用，一般用在过去完成时的句子里。它后面可以跟从句构成句型： It was/will be (not) long before . before 前一般是long, not long 等词。 值得注意的是：主句中的时态只能是一般过去时或一般将来时。It wasnt long before I found a job.我没花多少时间就找到了工作。It wont be long before our contry becomes a developed country.我们国家很快就会成为一个发达国家。It was long before he came back. 过了好久他才回来。It wont be long before we see each other. 不久我们又会见面的。before long 很快、不久=soon常用于将来时态。 I hope to see you before long. 我盼望不久就能见到你。 Weve seen that film long before. 我们早已看过那部电影了。 I had waited there long before he arrived. 他来之前，我在那已等了很久。单独的before作状语，可指现在以前，可用现在完成时态，请牢记，如： I have never been there before.1.Itwasnotuntil1936_basketballbecamearegularpartoftheOlympicGames.A. that B. when C. which D. then2.Itwillnotbe _wemeetagain.A. longbefore B. beforelong C. soonafter D. shortlyafter3.Hewasnearlydrownedonce.(02春招)Whenwas_？_wasin1998whenhewasinmiddleschool.A. that; It B. this; This C. this; It D. that; This4.Itwasevening _wereachedthelittletownofWinchester.(04天津)A. that B. until C. since D. before5.Scientistssayitmaybefiveorsixyears _itispossibletotestthismedicineonhumanpatients.(04福建)A. since B. after C. before D. when6.Itwas _ImetMr. SmithinLondon.A. manyyearsthat B. formanyyearssinceC. sincemanyyearsagowhen D. manyyearsagothat7.-Whatwasthepartylike？-Wonderful. Itsyears _Ienjoyedmyselfsomuch.A. after B. before C. when D. since8.Itwasabout600yearsago _thefirstclockwithafaceandanhourhandwasmade.A. that B. until C. before D. when(Keys：AAADCDDA) 关于it的几个重要考点，在此总结一下1. It was two years _he realized the truth. 2. It will be two years _ the economic situation improves.3. It was two years later _ he realized the truth.4. It is /has been two years _ he lived here.5. It was midnight _ he arrived home.6. It was at midnight _ he arrived home.7. It was not until midnight _ he arrived home.A. before B. when C. since D. that答案与解析1、2两个小题都选A. 第一题意为：两年后他才得知真相。第二题意为：经济形式要等两年后才会有所好转。归纳It was/ will be +一段时间+before+句子是高考一个重要考点。意为：多久之后才要注意：It will be +一段时间+before+句子，before引导的是一个时间状语从句，所以后面的从句要用一般现在时态表将来。3. D 此题为强调句型。把It wasthat去掉后，句子仍然成立：He realized the truth two years later.4. C 本句意为：他不住在这儿已经两年了。归纳为since意为自从某时或某事发生以来，故since后从句时，从句的时态应用一般过去时态，而主句应用现在完成时态。如表示某某事发生多久了，则用：It is/ has been+一段时间+since+从句。注意It is/ has been+一段时间+since+从句。在本结构中，从句的谓语动词如为延续性动词时