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1、Conditional Sentence 条件句Key PointsType I Type IV ConditionalsMixed Conditionals Replacing ifOmitting if if vs. when; in case vs. if 34.1 IntroductionConditional sentences consist of 2 partsone that expresses the conditionIntroduced by the word “if”, commonly known as “if clause”.one that expresses t
2、he consequence.Example: If you work hard, you will succeed. If a boy looks at me, I am flattered.There are four main types of conditional patterns.Type I : whenever-type real conditionalType II : probable real conditionalType III : improbable unreal conditionalType IV : imaginary unreal conditional3
3、4.2 Type I : whenever-type real conditionalUse: to denote universal truths or general validity to denote present habitual actions to denote past habitual actionsIf=when/whenever/every timeIf clausemain clause Simple present Simple pastSimple present Simple pastIf you pour oil on water, it floats. If
4、 I make a promise, If the weather was nice, I keep it.she often walked to work. 34.3 Type II : Probable Real ConditionalUsed for talking about possibilities in the present or in the future. If clausemain clause Simple Present will-future imperative modal + infinitive If I study, I will pass the exam
5、s. If you see John tonight, If Ben gets up early tell him to e-mail me. he can catch the bus. Exercise 1如果核武器用于世界大战，世界就会毁灭。 If nuclear weapons are employed in a world war, the world will be destroyed.Exercise 2Make up a sentence using the following phrases.Examplelazy, fail in exam If youre lazy, yo
6、ull be failed in the exam.1.not rain tomorrow, go for a picnic Answer 2.go to school on foot, late Answer 3.do not have breakfast, hungry Answer34.4 Type III: Improbable Unreal ConditionalUsed for talking about unreal situations in the present or in the future. If clausemain clause Simple Past would
7、 infinitive could infinitive might infinitive If I had a day off from work next week, I would go to the beach. I could go to the beach.I might go to the beach.Exercise 3年龄大的人如果离开农场，就会发现找份工作很难。The older men would find it difficult to get a job if they left the farm. 如果要问我的感受的话，我就会说“烦”。 If I were aske
8、d to define my condition, Id say “bored”.34.5 Type IV: Imaginary Unreal ConditionalUsed for talking about unreal situations in the past If clausemain clause (If) had ed-participle would have ed-participle. could have ed-participle.might have ed-participle.If I had studied, I would have passed the ex
9、ams. I could have passed the exams. I might have passed the exams. Exercise 4 如果她未结婚的话，她可能会在她的领域中有所成就。 If she had not married, she would probably have become something special in her field.Exercise 5Try to distinguish the following sentences.1.If you take a taxi, you can get there in time for the pl
10、ay. Type I Type II Type III Type IV 2.If I had known your arrival, I should have met you. Type I Type II Type III Type IV 3. If the weather is nice, she walks to work. Type I Type II Type III Type IV4.If I dropped this bomb, it would explode. Type I Type II Type III Type IV Exercise 55.If I were you
11、, I would not listen to him.Type I Type II Type III Type IV 6.If you had recognized him, you would have spoken to him.Type I Type II Type III Type IV 7. If I went to a friends house for dinner, I usually took a bottle of wine or some flowers. Type I Type II Type III Type IV 8. Set your alarm clock,
12、and you will not oversleep. Type I Type II Type III Type IV 34.6 Mixed Conditionals1 Sometimes Unreal Conditional sentences are mixed. This means that the time in the if-clause is not the same as the time in the result. PAST PRESENT If I had won the lottery, I would be rich. PAST FutureIf she had si
13、gned up for the ski trip last week, she would join us tomorrow. PRESENT PASTIf Sam spoke Russian, he would have translated the letter for you. 34.6 Mixed Conditionals2 Sometimes the validity of the if-clause is not the same as the validity of the result. Unreal RealI might have seen him, but he didn
14、t come to the party. Real UnrealHe isnt here now, or he would agree with me. He didnt come to the party, otherwise I might have seen him.butorotherwise34.7 Replacing ifIf can be replaced by words or expressions with a similar meaning.He is sure to come unless he has some urgent business. In case (th
15、at) he comes, let me know. I shall give you my dictionary on condition that you return it tomorrow. I will go, providing/provided (that) my expenses are paid. (granted/granting that)Suppose/Supposing (that) he does not come, what shall we do? (assume/assuming that)I will cooperate as long as I am no
16、tified on time. Exercise 6 TranslationWhat is questioned is whether a country like Britain has a chance, assuming it has the will, to succeed where so many have failed, and even assuming that it has, should make the tremendous effort and take substantial financial risk of trying to leap-frog into le
17、adership in entirely new technology, or whether it should take the softer option of merely catching up with the rest of the industrialized world.现在提出的问题是，像英国这样的国家，假如愿意的话，是否有可能在很多国家已经失败的方面获得成功。假如有这种可能，英国是否应尽最大的努力，冒重大财政风险，一步进入全新技术的前列，或者应该采取比较稳妥的选择，只是赶上其他工业国的步伐。 34.8 Omitting ifIf can be omitted with t
18、he if-clause partially invertedHad the doctor been available, the child would have been saved.Should it rain tomorrow, we would stay at home.Were I to go to the moon some day, I could see the surface of the moon with my own eyes.34.9 if vs whenBoth if and when are used in Type I Conditional. Using i
19、f suggests that something happens less frequently. Using when suggests that something happens regularly.If I have a day off from work, I usually go to the beach.I rarely have days off from work. When I have a day off from work, I usually go to the beach.I regularly have days off from work. I would b
20、uy that computer when it were cheaper. Not Correct I would buy that computer if it were cheaper. Correct34.10 if vs in casein case of can be used to shorten an if-clause as shown below: If there is a fire, leave the room.In case of fire, leave the room.While if expresses a condition (1), in case is
21、used to express a possibility (2).(1) I need painkillers if Im in severe pain.(2) I need painkillers in case Im in severe pain.The expression just in case is used pretty much the same way.I got you a pizza just in case you were hungry. (I dont know whether you are hungry.)Quiz1. (If / When) I leave
22、work, I usually go to the fitness center to work out.2. She hates TV. She thinks television is a waste of time. (If / When) she watches any television at all, it is usually a documentary or a news program.3. If I (have)_ enough money, I (go) _ on safari to Kenya. However, my bank account is empty!4.
23、 If you help me move tomorrow, I (treat)_ you to a dinner and a movie.5. If you were to help me move tomorrow, I (treat)_ you to a dinner and a movie.6. If Heather spoke Chinese, she (translate)_ the email for you yesterday. hadwould gowill treatwould treatwould have translated1.do not rain, go for
24、a picnic If it doesnt rain tomorrow, we shall go for a picnic.Please click here to next question !Please click here to next question !2. go on foot, late If you go to school on foot, youll be late.Please click here to next question !Please click here to next question !3.do not have breakfast, hungryIf you do not have breakfast, youll be hungry.Please click here to next question !Please click here to next question !
