由if和unless引導(dǎo)的條件狀語(yǔ)從句

1、由if和unless引導(dǎo)的條件狀語(yǔ)從句1. If we lose our short-term memory, we forget things happening recently.譯：2. If the picture is silly, strange and colorful, you will remember it better.譯：A: If sentences: actions with definite results.有必然結(jié)果發(fā)生的行動(dòng)eg: If you go into a clothes shop, you find clothes.1) If you go into

2、 a car showroom, you see cars.©Water turns into ice if you cool it.2) The wood floats if you put it into water.Conclusion:3) .如果if條件句談?wù)摰氖侵貜?fù)發(fā)生和預(yù)示必定要發(fā)生的情景和事件,那么主 從句大多用一般現(xiàn)在時(shí)態(tài).4) .在if條件句中,if條件從何可以放在前面,也可以放在后面.當(dāng) if引 導(dǎo)的條件從何放在前面時(shí),后面常用逗號(hào)隔開.B: If sentences: actions with possible results 有可能性結(jié)果發(fā)生的行動(dòng)eg: I

3、f you ask him, he will help you.如果你請(qǐng)他幫助,他會(huì)幫你的.If you fail in the exam , you will let him down .在if引導(dǎo)的條件狀語(yǔ)從句中,如果從何談?wù)摰氖且粋€(gè)有可能發(fā)生的事實(shí)及 其產(chǎn)生的相關(guān)的結(jié)果,主旬用一般將來(lái)時(shí)態(tài),從句用一般現(xiàn)在時(shí)態(tài).C: unless引導(dǎo)的條件狀語(yǔ)從句：unless= if not.conj.非,假設(shè)不,除非否那么e.g.: Let's go out for a walk unless you are too tired.=If you are not too tied, let

4、9;s go out for a walk.我們出去散步吧,除非是你太累.譯：如果你不早點(diǎn)出發(fā),你就不能及時(shí)趕到那兒.我們可以把unless； if not從何放在句子開頭或末尾.You will be late for school unless you leave now. =Unless you leave now, you will be late for school.除非你早點(diǎn)出發(fā),否那么你上學(xué)會(huì)遲到.You will be late for school if you don' t leave now.=If you don ' t leave now, you

5、will be late for schoo如果你不早點(diǎn)出發(fā),你上學(xué)遲 到.“if引導(dǎo)的條件狀語(yǔ)從句的用法,現(xiàn)在總結(jié)一下：1)引導(dǎo)條件狀語(yǔ)從句最常用的連詞是 if.if引導(dǎo)的條件句有真實(shí)條件句和非真 實(shí)條件句兩種(非真實(shí)條件句會(huì)在以后的虛擬語(yǔ)氣中闡述),其引導(dǎo)的真實(shí)條件 狀語(yǔ)從句表示在某種條件下某事很可能發(fā)生.2) if條件句不一般,幾個(gè)要點(diǎn)記心問(wèn)；條件句,放在前,逗號(hào)要放句中間.條件句表可能,主句多用將來(lái)時(shí)；條件旬表事實(shí),主句常用現(xiàn)在時(shí).【穩(wěn)固練習(xí)】1 .if和unless句型互改.Eg: You will fail the exam if you don' t work hard.

6、=You will fail the exam unless you work hard.1) Unless you obey the rules, you will be punished.=.2) A fish dies if you don ' t keep it in the water.3) No body can learn English well if he doesn' t work hard on it.4) Unless you start right now, you will be late for the meeting.2 .用if 或 unles

7、s填空.1. you put wood into water, it floats.2. I sleep with the window open it is really cold.3. You will not improve your skill in a short time you practice playing the violin regularly.4. Ice melts you heat it.5. you boil water, it becomes steam (蒸汽).6. you don ' t work hard, you will fail the e

8、xam.7. He can ' t be here on time he gets up early.8. you don ' t have enough sleep, you will feel tired.9. it is fine tomorrow, I will go fishing with my dad.10. you finish your homework, you will not go out to play.3 .單項(xiàng)選擇.1. You will not remember the facts you understand them well.A. ifB.

9、 unlessC. if notD. because2. Shenzhen a dirty place if we the ground.A. is; litterB. will be; will litter C. is; are litteringD. will be; litter3. If you harder, you will fail the exam.A. not work B. workC. don ' t work D. won' t work4. you obey the rules, you will be punished.A. IfB. SinceC

10、. BecauseD. Unless5. He can ' t see the words on the board unless he his glasses.A. wearB. wearsC. doesn ' t wear D. to wear6. If you plant seeds in soil,.A. it growsB. they grow C. you growD. it will grow7. If you check your timetable every night, it in your mind better.A. will stayB. stayC

11、. stayedD. staying8. A tourist will easily lose his way in Beijing he has a map or guide.A. ifB, becauseC. unlessD. when9. I shall telephone the police and complain about it the noiseA. if, stopsB. unless, stops10. I sleep with the window open itA. ifB. if notC. if not, stops s really cold.C. unlessD. unless, stopD. until11. you try, you will never succeed.A. IfB. UntilC. Since12. he doesn ' t come on time, weowilithout him.A. IfB. UnlessC. When13. I will come to see you if it rain tomorrow morning.A. won ' tB. didn ' t C. doesn ' t14. If you take a fish out of t