if引导的条件状语从句讲解和练习(答案)

if 引导的条件状语从句（作业）一、单项选择( )1. If you to the party, you’ll have a great time.A. will goB. wentC. goD. going( )2. I her the answer if she me.A. can tell, will askB. will tell, will askC. would tell, askD. will tell, asks( )3. —What are you going to do tomorrow?—We’ll go to the library tomorrow if it .A. isn’t rainB. rainC. won’t rainD. doesn’t rain( )4. —Do you know when he will come back tomorrow?—Sorry, I don’t know. When he back, I’ll tell you.A. comesB. will comeC. comeD. may come( )5. What will you do if you to the old folk’s home visit?A. goB. wentC. goingD. will go ( )6. I you up when he back.A. will wake; comeB. will wake; comesC. wake; comesD. wake; will come二、用所给词的适当形式填空(be) fewer trees, there ( be) 7.If theremore pollution.8.If Marcia (live) alone, she( keep) a pet dog.na (buy) a new dress if the old one(be) out of style.10.If Mr. Green (say) I am hard- working, myparents _ ( feel) glad.(go) to the beach if it11.I( not rain) this week.12.He (write) a letter to his grandparents if he(get) his report card this week.13.If she _ (get) up late, she( not catch) the early bus.三、根据汉语意思完成句子14.如果努力学习，你就会取得好成绩。

2019年秋八年级上册单元语法讲与练if引导的条件状语从句语法精讲1.条件状语从句的含义由一个主句和一个或一个以上的从句构成的句子叫复合句。

在复合句中作状语的句子叫作状语从句。

状语从句根据它表达的意思可分为很多种，if引导的句子在复合句中表示条件，作主句的条件状语，因此称为条件状语从句。

If you don’t hurry，you’ll be late.如果你不快点，你将会迟到的。

If he comes，let me know.如果他要来，通知我。

2.if引导的条件状语从句的结构if引导的条件状语从句在句中的位置比较灵活，可以放在主句之前(这时要和主句用逗号隔开)，也可以放在主句的后面(不用逗号)。

条件状语从句的结构为：if+陈述句，主语+谓语(=主语+谓语+if+陈述句)。

意为“如果……就……”。

If you ask him，he will tell you the answer.如果你问他，他就会告诉你答案。

I hope to visit her if I’m free.如果我有空，我希望去看望她。

3.if引导的条件状语从句与主句时态的一致性在复合句中，从句中动词的时态在一定程度上受到主句动词时态的制约，英语语法中称为时态呼应。

（1）在含有条件状语从句的复合句中，如果主句是一般将来时，从句则用一般现在时代替一般将来时表将来。

If it rains，I will stay at home.如果下雨，我将待在家里。

If you study hard，you will pass the examination.如果你努力学习，就能通过这次考试。

（2）如果主句含有must，may，can等情态动词，从句也要用一般现在时。

If you drive too fast，you may have an accident.如果你把车开得太快，你可能会出事故。

You must stop if the traffic light is red.如果红灯亮了，你必须停下来。

if引导的条件状语从句（讲义及答案）You will keep healthy if you do more exercise.If you do more exercise, you will keephealthy.1.时态：if 引导的条件状语从句用表示将来，主句可以使用一般将来时，含有情态动词的句子或者祈使句。

主将从现If you practice speaking English more, you will like itbetter. If she goes to New York tomorrow, I will go there,too.My sister will be very happy if our uncle comes next week.练习：If Nancy the exam, she will go to Australia forEnglish study.A.passB. passedC. passesD. will passIf the weather fine, we have a sports meeting next weekend.A. will be; willB. is; willC. was; wouldD. was; will主情从现If you get up at six tomorrow morning, you can catch the first bus. If you go to study in America next year, you must learn English hard.主祈从现Let’s go out for a walk if it doesn’t raintomorrow. If you see a snake in the forest, don’tmove!unless也可引导条件状语从句，表示“如果不，除非”Unless he comes here in an hour, I will go there alone.If he doesn’t come here in an hour, I will go therealone.You will feel worse unless you go to see the doctor right now.You will feel worse if you don’t go to see the do ctor right now.练习：you read it, you can’t imagine how interesting the story is.A. UnlessB. BecauseC. AlthoughD. If —Please give Alice the story book you see her.—All right.A.unlessB. orC. butD. ifExercises一、单项选择( )1. Studying in groups is necessary you want to do well in school.A.ifB. untilC. unlessD.though ( )2. —Will you help me with the trouble?—I won’t you tell me the truth.A. ifB. butC. afterD. unless( )3. If Bob away from the junk food, he will be in good health.A. stayB. will stayC. staysD.stayed ( )4. If Tom thegame, we’ll give him a surprise.A. winB. winsC. wonD.winning ( )5. We’ll go to the park if ittomorrow.A. won’t rainB. don’t rainC. doesn’t rainD.rain ( )6. If you’re more careful, youmuch better.A. doB. will doC. are doingD. did( )7. If there no buying and selling of animals, there no killing in nature.A. is; will beB. will be; will beC. is; isD. will be; is( )8. I’m waiting for my friend. If he ,Iswimming alone.A. doesn’t come; goB. won’t come; goC. won’t come; will goD. doesn’t come; will go二、翻译9.如果明天不下雨，我会去看你的。

If 引导的条件状语从句讲解与练习 If引导条件状语从句的条件状语从句最常用的连词是if，常见的if 条件状语从句表示在某条件下，某事很可能发生，条件是可能存在的。

如： If you ask him，he will help you．如果你请他帮忙，他会帮你的。

If you fail in the exam，you will let him down．如果你考试不及格，你会让他失望的。

If you have finished the homework， you can go home．如果你作业做完了就可以回家了。

1．if从句用一般现在时，主句用一般将来时If he runs he’ll get there in time.如果他用跑的，他就会及时赶到那儿。

The cat will scratch you if you pull her tail.如果你拉猫的尾巴，它就会抓你。

2．if从句用一般现在时，主句用may/might/can/must/shouldIf it stops snowing we can go out. 如果雪停了，我们就可以出去。

If you want to lose weight you must/should eat less bread.如果你想减肥，你必须少吃面包。

(另外，if从句还表示不可实现的条件或根本不可能存在的条件，也就是一种虚拟的条件或假设。

从句多用一般过去时或过去完成时，表示对现在或过去的一种假设。

如： If I were you，I would invite him to the party．如果我是你，我会邀请他参加聚会。

I would have arrived much earlier if I had not been caught in the traffic．要不是交通堵塞，我本会来得早一些。

)If条件状语从句练习( )1. If I find his phone number, I ______ you.A. tellB. toldC. will tellD. have told( )2. I __ the CDs to you if I have time tomorrow.A．will return B. returned C. have returned D. return ( )3. The students will go to the Summer Palace if it ________tomorrow.A. won' t rainB. isn' t rainingC. doesn' t rainD. isn't rain ( )4. I won’t watch the TV play if my father ___ me do my homework.A. letB. will letC. won’t letD. lets( )5. If you ___quiet, I’ll tell you what happened.A. willB. are C are to be D be( )6. If you go to the party, you ___ a good time.A. would haveB. haveC. will haveD. had( )7. Don’t worry. Peter will call you as soon as he _____ London.A. will get toB. gets toC. get toD. got to( ) 8.He doesn’t tell me when he __. I’ll telephone you as soon as he ___.A. will come, comesB. will come, will comeC. comes, will comeD. comes, comes( )9.-- I don’t know if Dr. White ______ to the party next week.–-- I think he will come if he ______ free.A. comes; will comeB. will come; will beC. comes; isD. will come; is( )10. I don’t know if there ____ a sports meeting next month.If they _____ it, I must get ready for it.A. is; will holdB. will be; holdC. will be; will holdD. will have; hold宾语从句练习( ) 1. I don’t know ___________________.A. what does he like bestB. what he like bestC. what he does like bestD. what he likes best( ) 2. Can you tell me ______________________?A. where she livesB. where does she liveC. she lives whereD. where she live( ) 3. He asked me _______________________________.A. what time is itB. what time it isC. what time was itD. what time it was( ) 4. Do you know _______________________?A. how much did it costB. how much it did costC. how much it costsD. how much does it cost( ) 5. The man asked her _______________________.A. why did she do itB. why she did itC. why she doesD. why does she do it( ) 6. Nobody knows _________________________.A. when will she come backB. when she come backC. when she will come backD. when does she come back ( ) 7. Mum asked _______________________________.A. where he wasB. where was heC. where he isD. where is he( ) 8. Do you know _______________________________?A. what they are looking forB. what are they looking for C, they are looking for what D. what do they look for ( ) 9. The teacher asked ________________________________.A, who can answer this questionB. who could answer the questionC. what question did she askD. she answered this question( ) 10. I asked her ______________________________.A. whether he has been to AustraliaB. whether has he been to AustraliaC. whether he had been to AustraliaD. whether he goes to Australia( ) 11. The teacher told us ________________________________.A. that light traveled faster than soundB. if light traveled faster than sound.C. that light travels faster than soundD. if light travels faster than sound( ) 12. He said that __________________________________.A. he is doing his homeworkB. he does his homeworkC. he was doing his homeworkD. he do his homework( ) 13. I asked him _________________________.A. where did he goB. where he wentC. where does he goD. where he did go( ) 14. --Excuse me, could you tell me _____ get to the plane? --Certainly. Go straight alone here.A. how can weB. how we canC. when can weD. when we can( ) 15. Do you know _____he will ride here at 8 tomorrow morning?A. whenB. whereC. whetherD. how( ) 16. --Can you tell me why __________________?--Because I want to help the people there.A. do you go to TibetB. did you go to TibetC. are you going to TibetD. you are going to Tibet ( ) 17. Do you know _______________________________?A. what time does the train leaveB. what time leaves the trainC. what time the train leaveD. what time the train leaves( ) 18. Could you tell me _______________________?A. who is heB. where’s the nearest restaurantC. if he will come tomorrowD. which way is to the underground station( ) 19. --Do you know ___________?--Sorry. I don’t know. You may ask the woman over there.A. when the shop opensB. when is the shop openC. when does the shop openD. when will the shop open ( ) 20 --Dad, do you know ____________? --In half an hour.A. when will the football game startB when the football game will startC. when is the football game going to startD. when shall we start the football game( ) 21. Could you tell me _______________________?A. which bus they are waiting forB. which bus are they waiting forC. they’re waiting for which busD. which bus they wait( ) 22. I asked her __________________________.A. whether did she like the red oneB. whether she likes the red oneC. whether does she like the red oneD. whether she liked the red one( ) 23. Can you guess (猜） __________the people in the picture are ?A. whenB. whomC. whoseD. who( ) 24. I’m thinking about ________________________________.A. if I’ll help herB. whether I’ll help herC. what I’ll help herD. that I help her( ) 25. --We never know _____________. --They say he is a teacher.A. what the old man isB. what is the old manC. who is the old manD. which the old man is10月份语法测试成绩 P40学生缴费日期表。

If 引导的条件状语从句讲解与练习If引导条件状语从句的条件状语从句最常用的连词是if，常见的if 条件状语从句表示在某条件下，某事很可能发生，条件是可能存在的。

如：If you ask him，he will help you．如果你请他帮忙，他会帮你的。

If you fail in the exam，you will let him down．如果你考试不及格，你会让他失望的。

If you have finished the homework，you can go home．如果你作业做完了就可以回家了。

1．if从句用一般现在时，主句用一般将来时If he runs he’ll get there in time.如果他用跑的，他就会及时赶到那儿。

The cat will scratch you if you pull her tail.如果你拉猫的尾巴，它就会抓你。

2．if从句用一般现在时，主句用may/might/can/must/shouldIf it stops snowing we can go out. 如果雪停了，我们就可以出去。

If you want to lose weight you must/should eat less bread.如果你想减肥，你必须少吃面包。

(另外，if从句还表示不可实现的条件或根本不可能存在的条件，也就是一种虚拟的条件或假设。

从句多用一般过去时或过去完成时，表示对现在或过去的一种假设。

如：If I were you，I would invite him to the party．如果我是你，我会邀请他参加聚会。

I would have arrived much earlier if I had not been caught in the traffic．要不是交通堵塞，我本会来得早一些。

)If条件状语从句练习( )1. If I find his phone number, I ______ you.A. tellB. toldC. will tellD. have told( )2. I __ the CDs to you if I have time tomorrow.A．will return B. returned C. have returned D. return( )3. The students will go to the Summer Palace if it ________tomorrow.A. won' t rainB. isn' t rainingC. doesn' t rainD. isn' t rain ( )4. I won’t watch the TV play if my fa ther ___ me do my homework.A. letB. will letC. won’t letD. lets( )5. If you ___quiet, I’ll tell you what happened.A. willB. are C are to be D be( )6. If you go to the party, you ___ a good time.A. would haveB. haveC. will haveD. had( )7. Don’t worry. Peter will call you as soon as he _____ London.A. will get toB. gets toC. get toD. got to( ) 8.He doesn’t tell me when he __. I’ll telephone you as soon as he ___.A. will come, comesB. will come, will comeC. comes, will comeD. comes, comes( )9.-- I don’t know if Dr. White ______ to the party next week.–-- I think he will come if he ______ free.A. comes; will comeB. will come; will beC. comes; isD. will come; is( )10. I don’t know if there ____ a sports meeting next month. If they _____ it, I must get ready for it.A. is; will holdB. will be; holdC. will be; will holdD. will have; hold宾语从句练习( ) 1. I don’t know ___________________.A. what does he like bestB. what he like bestC. what he does like bestD. what he likes best( ) 2. Can you tell me ______________________?A. where she livesB. where does she liveC. she lives whereD. where she live( ) 3. He asked me _______________________________.A. what time is itB. what time it isC. what time was itD. what time it was( ) 4. Do you know _______________________?A. how much did it costB. how much it did costC. how much it costsD. how much does it cost( ) 5. The man asked her _______________________.A. why did she do itB. why she did itC. why she doesD. why does she do it( ) 6. Nobody knows _________________________.A. when will she come backB. when she come backC. when she will come backD. when does she come back ( ) 7. Mum asked _______________________________.A. where he wasB. where was heC. where he isD. where is he( ) 8. Do you know _______________________________?A. what they are looking forB. what are they looking forC, they are looking for what D. what do they look for() 9. The teacher asked ________________________________.A, who can answer this questionB. who could answer the questionC. what question did she askD. she answered this question( ) 10. I asked her ______________________________.A. whether he has been to AustraliaB. whether has he been to AustraliaC. whether he had been to AustraliaD. whether he goes to Australia( ) 11. The teacher told us ________________________________.A. that light traveled faster than soundB. if light traveled faster than sound.C. that light travels faster than soundD. if light travels faster than sound( ) 12. He said that __________________________________.A. he is doing his homeworkB. he does his homeworkC. he was doing his homeworkD. he do his homework( ) 13. I asked him _________________________.A. where did he goB. where he wentC. where does he goD. where he did go( ) 14. --Excuse me, could you tell me _____ get to the plane?--Certainly. Go straight alone here.A. how can weB. how we canC. when can weD. when we can( ) 15. Do you know _____he will ride here at 8 tomorrow morning?A. whenB. whereC. whetherD. how( ) 16. --Can you tell me why __________________?--Because I want to help the people there.A. do you go to TibetB. did you go to TibetC. are you going to TibetD. you are going to Tibet( ) 17. Do you know _______________________________?A. what time does the train leaveB. what time leaves the trainC. what time the train leaveD. what time the train leaves( ) 18. Could you tell me _______________________?A. who is heB. where’s the nearest restaurantC. if he will come tomorrowD. which way is to the underground station( ) 19. --Do you know ___________?--Sorry. I don’t know. You may ask the woman over there.A. when the shop opensB. when is the shop openC. when does the shop openD. when will the shop open ( ) 20 --Dad, do you know ____________? --In half an hour.A. when will the football game startB when the football game will startC. when is the football game going to startD. when shall we start the football game( ) 21. Could you tell me _______________________?A. which bus they are waiting forB. which bus are they waiting forC. they’re waiting for which busD. which bus they wait( ) 22. I asked her __________________________.A. whether did she like the red oneB. whether she likes the red oneC. whether does she like the red oneD. whether she liked the red one( ) 23. Can you guess (猜）__________the people in the picture are ?A. whenB. whomC. whoseD. who( ) 24. I’m thinking about ________________________________.A. if I’ll help herB. whether I’ll help herC. what I’ll help herD. that I help her( ) 25. --We never know _____________. --They say he is a teacher.A. what the old man isB. what is the old manC. who is the old manD. which the old man is40学生缴费日期表。

If 引导的条件状语从句讲解与练习If引导条件状语从句的条件状语从句最常用的连词是if，常见的if条件状语从句表示在某条件下，某事很可能发生，条件是可能存在的。

如：If you ask him，he will help you．如果你请他帮忙，他会帮你的。

If you fail in the exam，you will let him down．如果你考试不及格，你会让他失望的。

If you have finished the homework，you can go home．如果你作业做完了就可以回家了。

1．if从句用一般现在时，主句用一般将来时If he runs he’ll get there in time.如果他用跑的，他就会及时赶到那儿。

The cat will scratch you if you pull her tail.如果你拉猫的尾巴，它就会抓你。

2．if从句用一般现在时，主句用may/might/can/must/shouldIf it stops snowing we can go out. 如果雪停了，我们就可以出去。

If you want to lose weight you must/should eat less bread.如果你想减肥，你必须少吃面包。

(另外，if从句还表示不可实现的条件或根本不可能存在的条件，也就是一种虚拟的条件或假设。

从句多用一般过去时或过去完成时，表示对现在或过去的一种假设。

如：If I were you，I would invite him to the party．如果我是你，我会邀请他参加聚会。

I would have arrived much earlier if I had not been caught in the traffic．要不是交通堵塞，我本会来得早一些。

)If条件状语从句练习( )1. If I find his phone number, I ______ you.A. tellB. toldC. will tellD. have told( )2. I __ the CDs to you if I have time tomorrow.A．will return B. returned C. have returned D. return( )3. The students will go to the Summer Palace if it ________tomorrow.A. won' t rainB. isn' t rainingC. doesn' t rainD. isn' t rain ( )4. I won’t watch the TV play if my father ___ me do my homework.A. letB. will letC. won’t letD. lets( )5. If you ___quiet, I’ll tell you what happened.A. willB. are C are to be D be( )6. If you go to the party, you ___ a good time.A. would haveB. haveC. will haveD. had( )7. Don’t worry. Peter will call you as soon as he _____ London.A. will get toB. gets toC. get toD. got to( ) 8.He doesn’t tell me when he __. I’ll telephone you as soon as he ___.A. will come, comesB. will come, will comeC. comes, will comeD. comes, comes( )9.-- I don’t know if Dr. White ______ to the party next week.–-- I think he will come if he ______ free.A. comes; will comeB. will come; will beC. comes; isD. will come; is( )10. I don’t know if there ____ a sports meeting next month. If they _____ it, I must get ready for it.A. is; will holdB. will be; holdC. will be; will holdD. will have; hold宾语从句练习( ) 1. I don’t know ___________________.A. what does he like bestB. what he like bestC. what he does like bestD. what he likes best ( ) 2. Can you tell me ______________________?A. where she livesB. where does she liveC. she lives whereD. where she live( ) 3. He asked me _______________________________.A. what time is itB. what time it isC. what time was itD. what time it was( ) 4. Do you know _______________________?A. how much did it costB. how much it did costC. how much it costsD. how much does it cost( ) 5. The man asked her _______________________.A. why did she do itB. why she did itC. why she doesD. why does she do it( ) 6. Nobody knows _________________________.A. when will she come backB. when she come backC. when she will come backD. when does she come back ( ) 7. Mum asked _______________________________.A. where he wasB. where was heC. where he isD. where is he( ) 8. Do you know _______________________________?A. what they are looking forB. what are they looking forC, they are looking for what D. what do they look for () 9. The teacher asked ________________________________.A, who can answer this questionB. who could answer the questionC. what question did she askD. she answered this question( ) 10. I asked her ______________________________.A. whether he has been to AustraliaB. whether has he been to AustraliaC. whether he had been to AustraliaD. whether he goes to Australia( ) 11. The teacher told us ________________________________.A. that light traveled faster than soundB. if light traveled faster than sound.C. that light travels faster than soundD. if light travels faster than sound( ) 12. He said that __________________________________.A. he is doing his homeworkB. he does his homeworkC. he was doing his homeworkD. he do his homework( ) 13. I asked him _________________________.A. where did he goB. where he wentC. where does he goD. where he did go( ) 14. --Excuse me, could you tell me _____ get to the plane?--Certainly. Go straight alone here.A. how can weB. how we canC. when can weD. when we can( ) 15. Do you know _____he will ride here at 8 tomorrow morning?A. whenB. whereC. whetherD. how ( ) 16. --Can you tell me why __________________?--Because I want to help the people there.A. do you go to TibetB. did you go to TibetC. are you going to TibetD. you are going to Tibet ( ) 17. Do you know _______________________________?A. what time does the train leaveB. what time leaves the trainC. what time the train leaveD. what time the train leaves( ) 18. Could you tell me _______________________?A. who is heB. where’s the nearest res taurantC. if he will come tomorrowD. which way is to the underground station( ) 19. --Do you know ___________?--Sorry. I don’t know. You may ask the woman over there.A. when the shop opensB. when is the shop openC. when does the shop openD. when will the shop open ( ) 20 --Dad, do you know ____________? --In half an hour.A. when will the football game startB when the football game will startC. when is the football game going to startD. when shall we start the football game。

if引导的条件状语从句引导条件状语从句最常用的连词是if，常见的if条件状语从句表示在某条件下，某事很可能发生，条件是可能存在的，主句中某种情况发生的概率也是很高的。

如：If you ask him,he will help you．如果你请他帮忙，他会帮你的。

If you fail in the exam,you will let him down．如果你考试不及格,你会让他失望的.If you have finished the homework， you can go home．如果你作业做完了就可以回家了.另外，if从句还表示不可实现的条件或根本不可能存在的条件，也就是一种虚拟的条件或假设。

从句多用一般过去时或过去完成时，表示对现在或过去的一种假设.如：If I were you，I would invite him to the party．如果我是你，我会邀请他参加聚会。

I would have arrived much earlier if I had not been caught in the traffic．要不是交通堵塞,我本会来得早一些。

另外你还要注意if 条件句的时态搭配1．if从句用一般现在时，主句用一般将来时If he runs he’ll get there in time. 如果他用跑的，他就会及时赶到那儿.The cat will scratch you if you pull her tail. 如果你拉猫的尾巴,它就会抓你。

2．if从句用一般现在时,主句用may/might/canIf the fog gets thicker the plane may/might be diverted. 如果雾在大一些，飞机可能就会改在别的机场降落。

If it stops snowing we can go out。

如果雪停了，我们就可以出去。

3．if从句用一般现在时,主句用must/shouldIf you want to lose weight you must/should eat less bread。

if条件状语从句练习题及答案If条件状语从句练习题及答案条件状语从句是英语中常用的一种从句结构，用来表示某个条件成立时，另一个事件或结果也将发生。

掌握条件状语从句的用法对于提高英语口语和写作能力非常重要。

下面将给出一些条件状语从句的练习题及答案，帮助读者更好地理解和掌握这一语法知识。

练习题一：1. If it rains tomorrow, ___________.2. She will be late for work if ___________.3. If I see him, ___________.4. If you don't study hard, ___________.5. If I were you, ___________.练习题二：1. If you ___________ to the party, please bring a gift.2. If I ___________ you, I would apologize.3. If she ___________ the exam, she will be very happy.4. If it ___________ tomorrow, we will go hiking.5. If he ___________ the bus, he will be late for the meeting.答案一：1. we will stay at home.2. she misses the bus.3. I will say hello.4. you will fail the test.5. I would study harder.答案二：1. come2. were3. passes4. doesn't rain5. misses通过以上练习题，我们可以发现条件状语从句的用法和特点。

首先，在条件状语从句中，通常使用的连词有if、unless、provided that等。

条件状语从句讲解――if引导的条件状语从句（注意&练习）在句子中做条件状语的从句称为条件状语从句。

可置于句首、句尾，有时还可置于主语和谓语之间。

引导条件状语从句的连接词有：if ,unless,as/so long as等1.if引导的条件状语从句表示在某种条件下某事很可能发生。

If we pay much attention to the earth, we'll have a better world.如果我们多关爱地球，就会拥有一个更美好的世界If it rains tomorrow, what shall we do?如果明天下雨，我们怎么办？注意：if还可以引导虚拟条件句，表示不可实现的条件，从句中多用一般过去时或过去完成时。

What would happen if there were no water ?如果没有水会怎样？2.unless引导的条件状语从句unless的意思是如果不，除非。

可与if...not互换。

You will fail in English unless you work hard.你英语考试会不及格的，除非你更加努力。

3.as /so long as引导的条件状语从句as /so long as意思是“只要”So long as you're happy,i will be happy.只要你高兴，我就高兴。

4.once引导的条件状语从句once引导的条件状语从句，意为“一旦...，就”，从句可置于主句前或后Once you begin,never stop.一旦开始，就绝不要停止Maths is easy to learn once you understand the rules.一旦你理解了规则，数学就不难学了。

提示：在条件状语从句中，用一般现在时代替一般将来时，用一般过去时代替过去将来时。

If the weather is bad next week, we'll put off the climbing.如果下周天气不好，我们将推迟爬山。

条件状语从句讲解――if引导得条件状语从句(注意&练习) 在句子中做条件状语得从句称为条件状语从句。

可置于句首、句尾,有时还可置于主语与谓语之间。

引导条件状语从句得连接词有:if ,unless,as/so long as等1、if引导得条件状语从句表示在某种条件下某事很可能发生。

If we pay much attention to the earth, we'll have a better world、如果我们多关爱地球,就会拥有一个更美好得世界If it rains tomorrow, what shall we do?如果明天下雨,我们怎么办？注意:if还可以引导虚拟条件句,表示不可实现得条件,从句中多用一般过去时或过去完成时。

What would happen if there were no water ?如果没有水会怎样？2、unless引导得条件状语从句unless得意思就是如果不,除非。

可与if、、、not互换。

You will fail in English unless you work hard、您英语考试会不及格得,除非您更加努力。

3、as /so long as引导得条件状语从句as /so long as意思就是“只要”So long as you're happy,i will be happy、只要您高兴,我就高兴。

4、once引导得条件状语从句once引导得条件状语从句,意为“一旦、、、,就”,从句可置于主句前或后Once you begin,never stop、一旦开始,就绝不要停止Maths is easy to learn once you understand the rules、一旦您理解了规则,数学就不难学了。

提示:在条件状语从句中,用一般现在时代替一般将来时,用一般过去时代替过去将来时。

If the weather is bad next week, we'll put off the climbing、如果下周天气不好,我们将推迟爬山。

i .单项选择1」f you ____ to the party, you ' II have a great time.a. will gob. wentc. god. going2」t will be a long time ___ peter _____ his work.a. since, has finishedb. after, finishesc. when, will finishd. before, finishes.3. what will father ___ us from Japan?a. takeb. bringc. carryd. make4. Weifang is famous _____ k itesa. forb. toc. ond. with5. I ___ her the answer if she ____ me.a. can tell, will askb. will tell, will askc. would tell, askd. will tell, asks6. -what are you going to do tomorrow?--we' ll go to the library tomorrow if it ___ .a. isn ' t rain rain c. won ' t raind. doesn ' t rain7. —Do you know when he will come back tomorrow?--sorry, I don' t know. when he ____ back,' ll tell you.a. comesb. will comec. comed. may come8. what will you do if you ____ to the old folk ' s home visit?a. gob. wentc. goingd. will go9. If I eat ___ food, I ' ll be very fat.a. too manyb. many tooc. too muchd. much too10」'll give the book to him if he ___ here next sunday.a. will comeb. comesc. is comingd. came11. There __ an english film in our school tomorrow.a. is going to haveb. will havec. is going to bed. has12. Could you tell us where __ ?a. will the next olympic games heldb. the next olympic games will be heldc. would the next olympic games be heldd. the next olympic games would be held13. When my mother returned last night,I ___ a book.a. readb. am readingc. was readingd. am going to read14. What ___ you ___ when it began to rain?a. do, dob. were, doingc. are, doingd. did, do15. I' ll wake you up when he ___ back.a. willb. is going to comec. comesd. comeII、用所给词的适当形式填空1. If you _____ (feel) tired, you ______ (have) to have a rest.2. Where ___ he _________ (see) the film if he _______ (have) time?3. If there ___ (be) fewer trees, there _______ (be) more pollution.4. He ____ (dress) more casually if he _______ (not work) on weekends.5」f marcia ______ (live) alone, she_______ (keep) a pet parrot.6. lana ____ (buy) a new dress if the old one ____ (be) out of style.7. The twins ____ (fight) if they _________ (argue).8. I ____ (have) a bake sale if I ____ (need) money for education.9. Peter ___ (send) me a beautiful souvenir if he ____ (tour) spain.10」f mr. green _____ (say) I am hard- working, my parents _____ (feel) glad.11. I _____ (go) to the beach if it _______ (not rain) this week.12. ___ t hey _____ (have) a match if the p.e. teacher ________ (be) busy?13. He ______ (write) a letter to his grandparents if he _______ (get) his report card this week.14. If she _____ (get) up late, she ______ (not catch) the early bus.15. Peter _______ (major) in English if he ________ (pass) the exams in peking university. III.完成句子1. 如果他到的晚了会发生什么事情？What ______________ if he _____________ late?2. 如果努力学习，你就会取得好成绩。

条件状语从句一、条件状语从句通常由if（如果）, unless（除非），as long as（只要）引导。

例如：If it rains tomorrow, we won’t go to the park. 如果明天下雨，我们就不去公园了。

Unless weather stops me, I go for a walk every. 我每天都会去散步，除非遇上坏天气。

Our parents will be pleased with our performance as long as we try our best.小试牛刀：1、只要我们竭尽全力，父母就会满意我们的表现。

Our parents will be pleased with our performance _____ _____ ______ we try our best.2、如果人人为保护环境做出贡献，世界将会变得更美好。

______ ______ ______ _____ _______ to protecting the environment, the world will become much more beautiful.二、if引导的条件状语从句（1）“if从句+祈使句”的句子。

其实，if作为一个连词，主句也可以是其他形式的句子。

例如：If you want to go, please let me know.If the green light isn’t on, wait for a minute.(2)“祈使句+ and (or)+ 陈述句” 在意思上相当于一个带有条件状语从句的复合句。

注意：A. “祈使句+ and + 陈述句”可以转化为if引导的肯定条件状语从句，而且主语是第二人称。

B. “祈使句+ or + 陈述句”可以转化为if引导的否定条件状语从句，而且主语是第二人称。

例如：Study hard and you will pass the exam. =If you study hard, you will pass the exam.Hurry up, or you’ll be late. =If you don’t hurry up, you’ll be late.考题(2010重庆中考)Work hard，________ you may catch up with your classmates soon.A.orB.butC.andD.yet思路解析：本句是“祈使句＋and”的句型，句意为“努力学习，你会很快赶上其他同学的”，and在句中表示承接关系，所以选C项。

if用法详解(含练习和答案)If的用法一、if作为连词，引导条件状语从句，表示“假如”“如果”等。

在复合句中，如果主句使用将来时，则if引导的状语从句使用一般现在时。

例如：1.如果天不下雨，下周星期天我们将去公园。

2.如果你请求他，他将会帮助你。

二、if还可以引导让步状语从句。

这时if相当于“即使是”，“虽说”。

例如：1.虽然她很穷，但至少她还是诚实的。

2.即使我错了，那么你也不对。

3.虽然会花费我一下午的时间，我还是要做这件事。

三、if作为连词还可以引导宾语从句。

引导宾语从句时和whether意思相同。

例如：1.XXX问她是否喜欢它。

2.她问他们是否有一件棉织的。

四、用于虚拟语气中，if从句中使用过去式，表示不可能实现、大概不会实现或提出作为考虑的假定条件。

例如：1.假使你是只鸟，你便会飞了。

2.如果我向他借贷，他会答应吗？另外，if从句中使用过去完成式，表示过去未实现的条件（例如由于不可能实现或某人未能实行）。

例如：1.要是他们早些动身，他们便可及时到达了。

2.如果他们那时不动身，现在他们就不会在此地了。

人一样。

2.As if by magic，the XXX.)花儿一夜之间就像魔法一样开了。

其次，unless与if连用，表示“除非”的意思。

例如：1.Unless you work hard，you won’t succeed．(If you don’t work hard。

you won’t succeed.)除非你努力工作，否则你不会成功。

2.I won’t go unless you come with me．(If you don’t com e with me。

I won’t go.)除非你和我一起去，否则我不会去。

最后，suppose与if连用，表示“假设、设想”的意思。

例如：1.Suppose it rains tomorrow，what will you do。

(If it rains tomorrow。

八年级英语‎：i f引导的‎条件状语从‎句常见的if‎条件状语从‎句表示在某‎条件下，某事很可能‎发生，条件是可能‎存在的，主句中某种‎情况发生的‎概率也是很‎高的。

如：If you ask him，he will help you．如果你请他‎帮忙，他会帮你的‎。

If you fail in the exam，you will let him down．如果你考试‎不及格，你会让他失‎望的。

If you have finis‎h ed the homew‎o rk，you can go home．如果你作业‎做完了就可‎以回家了。

另外，if从句还‎表示不可实‎现的条件或‎根本不可能‎存在的条件‎，也就是一种‎虚拟的条件‎或假设。

从句多用一‎般过去时或‎过去完成时‎，表示对现在‎或过去的一‎种假设。

如：If I were you，I would‎invit‎e him to the party‎．如果我是你‎，我会邀请他‎参加聚会。

(不能用wa‎s)I would‎have arriv‎e d much earli‎e r if I had not been caugh‎t in the traff‎i c．要不是交通‎堵塞，我本会来得‎早一些。

另外你还要‎注意if 条件句的时‎态搭配1．if从句用‎一般现在时‎，主句用一般‎将来时If he runs ，he’ll‎get‎there‎in time.如果他用跑‎的，他就会及时‎赶到那儿。

The cat will scrat‎c h you if you pull her tail.如果你拉猫‎的尾巴，它就会抓你‎。

2. if从句用‎一般现在时‎，主句用ma‎y/might‎/canIf the fog gets thick‎e r the plane‎may/might‎be diver‎t ed.如果雾在大‎一些，飞机可能就‎会改在别的‎机场降落。

if引导的条件状语从句引导条件状语从句最常用的连词是if，常见的if条件状语从句表示在某条件下，某事很可能发生，条件是可能存在的，主句中某种情况发生的概率也是很高的。

如：If you ask him，he will help you．如果你请他帮忙，他会帮你的。

If you fail in the exam，you will let him down．如果你考试不及格，你会让他失望的。

If you have finished the homework，you can go home．如果你作业做完了就可以回家了。

另外，if从句还表示不可实现的条件或根本不可能存在的条件，也就是一种虚拟的条件或假设。

从句多用一般过去时或过去完成时，表示对现在或过去的一种假设。

如：If I were you，I would invite him to the party．如果我是你，我会邀请他参加聚会。

I would have arrived much earlier if I had not been caught in the traffic．要不是交通堵塞，我本会来得早一些。

另外你还要注意if 条件句的时态搭配1．if从句用一般现在时，主句用一般将来时If he runs he’ll get there in time. 如果他用跑的，他就会及时赶到那儿。

The cat will scratch you if you pull her tail. 如果你拉猫的尾巴，它就会抓你。

2．if从句用一般现在时，主句用may/might/canIf the fog gets thicker the plane may/might be diverted. 如果雾在大一些，飞机可能就会改在别的机场降落。

If it stops snowing we can go out. 如果雪停了，我们就可以出去。

3．if从句用一般现在时，主句用must/shouldIf you want to lose weight you must/should eat less bread. 如果你想减肥，你必须少吃面包。

初中英语：条件状语从句一. 条件状语从句的概念条件状语从句，即在某种条件下，一件事情可能发生。

在英语中由连接词if或unless等引导的状语从句叫做条件状语从句。

条件是指某一件事情实现之后（状语从句中），一件事情（主句）才能发生，通常译作假如，只要，如果”等意思。

条件状语从句中，主从句的时态要遵循生将从现”的原则。

即，主句是将来时态时，从句用一般现在时代替将来时态。

二. 条件状语从句的引导词1.If conj .如果，假如If you ask him , he will help you . 如果你请他帮忙，他会帮你的。

If you fail in the exam , you will let him down . 如果你考试不及格，你会让他失望的。

2. ............................................................ unless conj.除非，若不，除非在的时候（if...not...）You will fail to arrive there in time unless you start earlier. 如果你不早点动身，你就不能及时赶到那儿。

Unless it rains, the game will be played. 除非下雨，比赛将照常进行。

3. so/as long as conj. 只要You may borrow my book as long as you keep it clean.只要你保持书的清洁，你就可以把我的书借去。

三. 关丁条件句的时态，常见的有以下三种情况：1、条件状语从句的主句是一般将来时，那么从句常常用一般现在时。

When I grow up, I ' ll be a nurse and look after patients.我长大后要当一名护士，照顾病人。

2、如果主句是祈使句，那么从句通常要用一般现在时。

If 引导的条件状语从句讲解与练习If引导条件状语从句的条件状语从句最常用的连词是if，常见的if条件状语从句表示在某条件下，某事很可能发生，条件是可能存在的。

如：If you ask him，he will help you．如果你请他帮忙，他会帮你的。

If you fail in the exam，you will let him down．如果你考试不及格，你会让他失望的。

If you have finished the homework，you can go home．如果你作业做完了就可以回家了。

1．if从句用一般现在时，主句用一般将来时If he runs he’ll get there in time.如果他用跑的，他就会及时赶到那儿。

The cat will scratch you if you pull her tail.如果你拉猫的尾巴，它就会抓你。

2．if从句用一般现在时，主句用may/might/can/must/shouldIf it stops snowing we can go out. 如果雪停了，我们就可以出去。

If you want to lose weight you must/should eat less bread.如果你想减肥，你必须少吃面包。

(另外，if从句还表示不可实现的条件或根本不可能存在的条件，也就是一种虚拟的条件或假设。

从句多用一般过去时或过去完成时，表示对现在或过去的一种假设。

如：If I were you，I would invite him to the party．如果我是你，我会邀请他参加聚会。

I would have arrived much earlier if I had not been caught in the traffic．要不是交通堵塞，我本会来得早一些。

)If条件状语从句练习( )1. If I find his phone number, I ______ you.A. tellB. toldC. will tellD. have told( )2. I __ the CDs to you if I have time tomorrow.A．will return B. returned C. have returned D. return( )3. The students will go to the Summer Palace if it ________tomorrow.A. won' t rainB. isn' t rainingC. doesn' t rainD. isn' t rain ( )4. I won’t watch the TV play if my father ___ me do my homework.A. letB. will letC. won’t letD. lets( )5. If you ___quiet, I’ll tell you what happened.A. willB. are C are to be D be( )6. If you go to the party, you ___ a good time.A. would haveB. haveC. will haveD. had( )7. Don’t worry. Peter will call you as soon as he _____ London.A. will get toB. gets toC. get toD. got to( ) 8.He doesn’t tell me when he __. I’ll telephone you as soon as he ___.A. will come, comesB. will come, will comeC. comes, will comeD. comes, comes( )9.-- I don’t know if Dr. White ______ to the party next week.–-- I think he will come if he ______ free.A. comes; will comeB. will come; will beC. comes; isD. will come; is( )10. I don’t know if there ____ a sports meeting next month. If they _____ it, I must get ready for it.A. is; will holdB. will be; holdC. will be; will holdD. will have; hold宾语从句练习( ) 1. I don’t know ___________________.A. what does he like bestB. what he like bestC. what he does like bestD. what he likes best( ) 2. Can you tell me ______________________?A. where she livesB. where does she liveC. she lives whereD. where she live( ) 3. He asked me _______________________________.A. what time is itB. what time it isC. what time was itD. what time it was( ) 4. Do you know _______________________?A. how much did it costB. how much it did costC. how much it costsD. how much does it cost( ) 5. The man asked her _______________________.A. why did she do itB. why she did itC. why she doesD. why does she do it( ) 6. Nobody knows _________________________.A. when will she come backB. when she come backC. when she will come backD. when does she come back ( ) 7. Mum asked _______________________________.A. where he wasB. where was heC. where he isD. where is he( ) 8. Do you know _______________________________?A. what they are looking forB. what are they looking forC, they are looking for what D. what do they look for ( ) 9. The teacher asked ________________________________.A, who can answer this questionB. who could answer the questionC. what question did she askD. she answered this question( ) 10. I asked her ______________________________.A. whether he has been to AustraliaB. whether has he been to AustraliaC. whether he had been to AustraliaD. whether he goes to Australia( ) 11. The teacher told us ________________________________.A. that light traveled faster than soundB. if light traveled faster than sound.C. that light travels faster than soundD. if light travels faster than sound( ) 12. He said that __________________________________.A. he is doing his homeworkB. he does his homeworkC. he was doing his homeworkD. he do his homework( ) 13. I asked him _________________________.A. where did he goB. where he wentC. where does he goD. where he did go( ) 14. --Excuse me, could you tell me _____ get to the plane?--Certainly. Go straight alone here.A. how can weB. how we canC. when can weD. when we can( ) 15. Do you know _____he will ride here at 8 tomorrow morning?A. whenB. whereC. whetherD. how( ) 16. --Can you tell me why __________________?--Because I want to help the people there.A. do you go to TibetB. did you go to TibetC. are you going to TibetD. you are going to Tibet ( ) 17. Do you know _______________________________?A. what time does the train leaveB. what time leaves the trainC. what time the train leaveD. what time the train leaves( ) 18. Could you tell me _______________________?A. who is heB. where’s the nearest restaurantC. if he will come tomorrowD. which way is to the underground station( ) 19. --Do you know ___________?--Sorry. I don’t know. You may ask the woman over there.A. when the shop opensB. when is the shop openC. when does the shop openD. when will the shop open ( ) 20 --Dad, do you know ____________? --In half an hour.A. when will the football game startB when the football game will startC. when is the football game going to startD. when shall we start the football game( ) 21. Could you tell me _______________________?A. which bus they are waiting forB. which bus are they waiting forC. they’re waiting for which busD. which bus they wait( ) 22. I asked her __________________________.A. whether did she like the red oneB. whether she likes the red oneC. whether does she like the red oneD. whether she liked the red one( ) 23. Can you guess (猜）__________the people in the picture are ?A. whenB. whomC. whoseD. who( ) 24. I’m thinking about ________________________________.A. if I’ll help herB. whether I’ll help herC. what I’ll help herD. that I help her( ) 25. --We never know _____________. --They say he is a teacher.A. what the old man isB. what is the old manC. who is the old manD. which the old man is40aaaaa 学生缴费日期表aa。

条件状语从句引导词：if(如果) ,unless(除非), in case(以防)时态：主将从现(可能会发生的事情)主现从现(肯定会发生/祈使句)1.if引导的条件状语从句，可位于前面或后面，但是如果放在后面，主从句用逗号隔开。

e.g.I will call you if I come. 或If I come, I will come.(主将从现)如果明天不下雨，我们将去野炊。

_____________________________________________If you drop the vase,it falls into pieces.(主现从现) 如果你摔花瓶的话，它就会变成碎片。

如果你把水冷却的话，它就会变成冰。

_______________________________________________If you have any problems,please call me.如果你知道答案，请举手。

_______________________________________________2.unless引导的条件状语从句，位置和if引导的一样。

Unless=if...notE.g. If you don't study hard,you will not pass the exam.=Unless you study hard,you will not pass the exam.除非你努力工作，否则你不会得到高工资。

（high salary）。

___________________________________________________________________________________________________________________3.条件状语从句和祈使句之间的转换。

结构：祈使句，and/or +从句（and:那么or否则）1.)Work hard,and you will get a high salary.=If you work hard, you will get a high salary.2.)Work hard,or you will not get a high salary.=Unless you work hard, you will not get a high salary.=If you don't work hard, you will not get a high salary.练习一．在正确的答案下划一条线。

if 引导的条件状语从句（讲义）状语用来表示行为发生的时间、地点、目的、方式、程度等，通常由副词或介词短语充当，也可由一个句子充当。

I slept at home yesterday because I had a bad cold.状语从句状语从句指句子作状语。

根据其作用可分为时间、地点、原因、条件、目的、结果、让步、方式等从句。

状语从句一般由连词(从属连词)引导。

I will go to school by bike tomorrow if it is sunny.Grammar focus—I think I’ll take the bus to the party.—If you do, you’ll be late.If you take the bus to the party, you’ll be late.—I think I’ll stay at home.—If you do, you’ll be sorry.If you stay at home, you’ll be sorry.—What will happen if they have the party today?—If they have it today, half the class won’t come.—Should we ask people to bring food?—If we ask people to bring food, they’ll just bring potato chipsand chocolate.1.if 在本单元句中意为“；”，用于引导即 if 引导的是一个完整的句子，所以一定要有主谓，成为从句，另一个句子则成为主句。

If you go there, I’ll go, too.We will go hiking if it doesn’t rain tomorrow.If Bob leaves tomorrow, I will hold a party for him tonight.2.if 引导的条件状语从句既可以放在主句前，也可放在主句后。