条件状语从句完整精.ppt

条件状语从句完整课件第1页，本讲稿共13页条件状语从句条件状语从句l l 引导条件状语从句最常用的连词是引导条件状语从句最常用的连词是if，常见的常见的if条件状语从句表示在某条件下，某条件状语从句表示在某条件下，某事很可能发生事很可能发生 l lIf youIf you ask ask him him，he he will helpwill help you youl l如果你请他帮忙，他会帮你的。如果你请他帮忙，他会帮你的。l lIf you If you fail fail in the examin the exam，you you will letwill let him him downdownl l如果你考试不及格，你会让他失望的。如果你考试不及格，你会让他失望的。第2页，本讲稿共13页l l如果你作业做完了就可以回家了。如果你作业做完了就可以回家了。l l If you If you have finishedhave finished the homework the homework，you you can gocan go home.home.第3页，本讲稿共13页1.If 从句从句（一般现在时），（一般现在时），主句主句（一般现在时一般现在时）l l表示科学常识，说明，表示科学常识，说明，经常性的动作，倾向经常性的动作，倾向 自动会发生的事自动会发生的事 l l1.If water 1.If water is heatedis heated,it,it turnsturns to steam.to steam.l l2.If people 2.If people dont getdont get enough sleep,their enough sleep,their thinking ability thinking ability is reducedis reduced.l l3.If I 3.If I needneed a haircut,I usually a haircut,I usually gogo to the to the barbers near where I live.barbers near where I live.l l4.People often 4.People often dont godont go out on Sundays if it out on Sundays if it rainsrains.第4页，本讲稿共13页2表示将来的可能性，能力，表示将来的可能性，能力，允诺，命允诺，命令，要求，请求，建议时，令，要求，请求，建议时，运用运用“主将从现主将从现”的原则。的原则。l l1.If I 1.If I getget the job,I the job,Ill buyll buy a mobile phone.a mobile phone.l l2.If my homework 2.If my homework is is difficult,I difficult,Ill askll ask Helen to Helen to help me.help me.l l3.If I 3.If I havehave time this afternoon,I time this afternoon,Ill goll go to the to the barbers to get a haircut.barbers to get a haircut.第5页，本讲稿共13页那么，除了那么，除了if之外，是否还有其他连词可之外，是否还有其他连词可以引导条件状语从句呢以引导条件状语从句呢 l l 回答是肯定的。不仅有，还有很多。这回答是肯定的。不仅有，还有很多。这些词由于出现的频率小，且用法较复杂一些些词由于出现的频率小，且用法较复杂一些，所以不如，所以不如if为大家所熟知罢了。下面就这为大家所熟知罢了。下面就这些词的用法做一介绍。些词的用法做一介绍。第6页，本讲稿共13页1unless 除非；若不；如果不除非；若不；如果不；除；除非在非在时候时候 l l1.You will fail to arrive there in time 1.You will fail to arrive there in time unless unless you you start earlierstart earlierl l如果你不早点动身，你就不能及时赶到那儿。如果你不早点动身，你就不能及时赶到那儿。2.2.UnlessUnless bad weather stops me bad weather stops me，I go for a I go for a walk every morningwalk every morningl l除非天气不好，我每天早晨都要去散步。除非天气不好，我每天早晨都要去散步。l l3.I wont loan you 3.I wont loan you unlessunless you are in extreme you are in extreme need of moneyneed of moneyl l若不是你急需用钱，我不会借钱给你的。若不是你急需用钱，我不会借钱给你的。第7页，本讲稿共13页2 2on condition thaton condition that只有在只有在条件下，条件下，以以为条件为条件 l lon condition thaton condition that引导的条件从句是主句中事引导的条件从句是主句中事件发生的件发生的前提条件或唯一条件。前提条件或唯一条件。l lI can tell you the truth I can tell you the truth on condition thaton condition that you you promise to keep a secretpromise to keep a secretl l我可以告诉你真相，条件是你答应保守秘密。我可以告诉你真相，条件是你答应保守秘密。l lYou can pass the custom You can pass the custom on condition thaton condition that we have checked your luggagewe have checked your luggage你可以通过你可以通过海关，但条件是我们得检查完你的行李。海关，但条件是我们得检查完你的行李。第8页，本讲稿共13页3 3supposing(that)conjsupposing(that)conj假若，倘若假若，倘若 l lsupposingsupposing 引导的从句表示一种引导的从句表示一种假设条件假设条件。通常。通常在句首在句首 l lSupposingSupposing it rains it rains，shall we continue the sports shall we continue the sports meetingmeeting？l l倘若下雨，我们的运动会还会继续进行吗？倘若下雨，我们的运动会还会继续进行吗？l lSupposingSupposing the stocks of food run out the stocks of food run out，what what shall we doshall we do？l l假若储备的食品都吃光了，我们怎么办呢？假若储备的食品都吃光了，我们怎么办呢？第9页，本讲稿共13页4 4provided that./providing(that)conjprovided that./providing(that)conj假若假若 l lprovided/providing provided/providing（thatthat）从句）从句 表示一种表示一种假设条件。假设条件。l lHe will sign the contract He will sign the contract provided(that)provided(that)we offer we offer more favorable termsmore favorable termsl l如果我们提出更优惠的条件，他就会在合同上签如果我们提出更优惠的条件，他就会在合同上签字。字。l lHe wont be against us in the meeting He wont be against us in the meeting providing providing(that)(that)we ask for his advice in advance we ask for his advice in advancel l如果我们提前征求一下他的意见，他就不在会上如果我们提前征求一下他的意见，他就不在会上反对我们。反对我们。第10页，本讲稿共13页5.as(so)long as.“5.as(so)long as.“只要只要，就就 ”表示表示 一种前提条件一种前提条件l lYoull succeed Youll succeed as(so)long as(if only)as(so)long as(if only)you try hard.you try hard.l l只要你努力，你就会成功。只要你努力，你就会成功。第11页，本讲稿共13页but forbut for +短语，短语，要不是要不是l l6.6.But for the rainBut for the rain，we we should haveshould have a pleasant a pleasant journeyjourneyl l要不是下雨，我们的旅行肯定很愉快。要不是下雨，我们的旅行肯定很愉快。l l=If it=If it didnt raindidnt rain,we,we should haveshould have a pleasant a pleasant journey.journey.l lBut for your help,we But for your help,we should not have should not have finishedfinished the task in time the task in timel l要不是你帮忙，我们肯定不能及时完成任务。要不是你帮忙，我们肯定不能及时完成任务。l l=If you=If you hadnt helpedhadnt helped us,we us,we should not have should not have finishedfinished the task in time the task in time.第12页，本讲稿共13页Without.+Without.+短语，短语，如果没有如果没有.l l7.7.Without water,there Without water,there would bewould be no life no life on earth at allon earth at all如果没有水，地球上就不如果没有水，地球上就不会有生命。会有生命。l l=If there=If there werewere no water,there no water,there would bewould be no no life on earth at all.life on earth at all.第13页，本讲稿共13页