由if和unless引导的条件状语从句
1. If we lose our short-term memory, we forget things happening recently.
译：
2. If the picture is silly, strange and colorful, you will remember it better. 译：
A: If sentences: actions with definite results.有必然结果发生的行动eg:① If you go into a clothes shop, you find clothes.
②If you go into a car showroom, you see cars.
③Water turns into ice if you cool it.
④The wood floats if you put it into water.
Conclusion:
1) . 如果if 条件句谈论的是重复发生和预示必定要发生的情景和事件，则主从句大多用一般现在时态。
2) . 在if 条件句中，if 条件从句可以放在前面，也可以放在后面。当if 引导的条件从句放在前面时，后面常用逗号隔开。
B: If sentences: actions with possible results 有可能性结果发生的行动eg: 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．
在if 引导的条件状语从句中,如果从句谈论的是一个有可能发生的事实及其产生的相关的结果，主句用一般将来时态，从句用一般现在时态。
C: unless引导的条件状语从句：unless= if ......... not. con除非，若不，除非???(否
则)
e.g.: Let's go out for a walk unless you are too tired.
= If you are not too tied, let's go out for a walk. 我们出去散步吧，除非是你太累。译：如果你不早点出发,你就不能及时赶到那儿。
我们可以把unless或if…not从句放在句子开头或末尾。
You will be late for school unless you leave now. = Unless you leave now, you will be late for school. 除非你早点出发，（否则）你上学会迟到。
You will be late for school if you don 't leave now. =
If you don ' t leave now, you will be late for schoo如果你不早点出发，你上学迟
1. If we lose our short-term memory, we forget things happening recently.译：
到。
“if引导的条件状语从句的用法，现在总结一下：
1) 引导条件状语从句最常用的连词是if o if引导的条件句有真实条件句和非真实条件句两种(非真实条件句会在以后的虚拟语气中阐述)，其引导的真实条件状语从句表示在某种条件下某事很可能发生。
2) if条件句不一般，几个要点记心间；条件句，放在前，逗号要放句中间。
条件句表可能，主句多用将来时；条件句表事实，主句常用现在时。
【巩固练习】
一.if和uni ess句型互改。
Eg: You will fail the exam if you don ' t work hard.
=You will fail the exam uni ess you work hard.
1) Uni ess you obey the rules, you will be puni shed.
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) Un less you start right now, you will be late for the meet ing.
二.用if 或uni ess 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 playi ng 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 exam.
7. He can ' t be here on time _____ he gets up early.
8. ______ you don ' t have eno ugh 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.
三.单项选择。
1. You will not remember the facts ______ you understand them well.
A. if
B. uni ess
C. if not
D. because
2. Shenzhen ______ a dirty place if we ______ the ground.
A. is; litter
B. will be; will litter
C. is; are litteri ng
D. will be; litter
3. If you ______ harder, you will fail the exam.
A. not work
B. work
C. don ' t work
D. won ' t work
4. _____ you obey the rules, you will be punished.
A. If
B. Since
C. Because
D. Uni ess
5. He can ' t see the words on the board uni ess he his glasses.
A. wear
B. wears
C. doesn ' t wear
D. to wear
6. If you pla nt seeds in soil, _____ .
A. it grows
B. they grow
C. you grow
D. it will grow
7. If you check your timetable every night, it _____ in your mind better.
A. will stay
B. stay
C. stayed
D. stayi ng
8. A tourist will easily lose his way in Beiji ng ____ he has a map or guide.
A. if B, because C. uni ess D. whe n
9. I shall teleph one the police and compla in about it ____ t he no ise
A. if, stops
B. uni ess, stops
10. I sleep with the window open ______ it A. if B. if not 11. _____ y ou try, you will n ever succeed. A. If B. U ntil C. Since
12. _____ h e doesn ' t come on time, wgowiMthout him.
A. If
B. U nless
C. When
13. I will come to see you if it _____ rain tomorrow morni ng.
A. won ' t
B. didn 't
C. doesn 't
14. If you take a fish out of the water, it _____ .
A. die
B. dies
C. will die
15. ---Shall Tony come and play computer games?
---No, _____ he has fini shed his homework.
A. whe n
B. if
C. uni ess C. if not, stops
s really cold.
C. uni ess
D. uni ess, stop D. until D. Un less D. Because D. don 't D. has died
D. once
if引导的条件状语从句讲解和练习(答案)
t 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 ’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.or B.but C.and D.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。答案：C 黑色陷阱：本题的陷阱是句型，本句型区别于“祈使句＋or”，这个句型的含义是“……，不然的话/否则……”。 绿色通道：祈使句后面既可以加 and ，也可以加 or ，所以要全面分析句意，再作决定。 小试牛刀：用 if 连接下列句子 1、Go to bed early and you will have a good rest. 2、Hurry up, or you ’ll miss the bus. 三、if 从句与主句具有以下特点： 1．If 从句中用一般现在时，表示未来的一种条件，从句中可以加时间状语。 e.g.If yo u can’t come tomorrow, we can hold the party a little later.明天你如果不能来，我们可迟一点举行宴会。
让步、条件状语从句
条件状从和让步状从练习 一．单选题 1._______ the forest park is far away, a lot of tourists visit it every year. A. As B. When C. Even though D. In case 2. The experiment shows that proper amounts of exercise, if ______ regularly, can improve our health. A. being carried out B. carrying out C. carried out D. to carry out 3. You will never gain success you are fully devoted to your work. A. when B. because C. after D. unless 4. It is hard for the Greek government to get over the present difficulties_________ it gets more financial support from the European Union. A. if B. unless C. because D. since 5. It was a nice meal, _______a little expensive. A. though B. whether C. as D. since 6. I don’t really like the author,_______ I have to admit his books are very exciting. A. although B. unless C. until D. once 7. I don't believe we've met before, _____ I must say you do look familiar. A. therefore B. although C. since D. unless 8. You can’t borrow books from the school library ______ you get your student card. A. unless B. if C. while D. as 9. I'll be out for some time. ______ anything important happens, call me up immediately. A. In case B. As if C. Even though D. Now that 10. One's life has value ____one brings value to the life of others. A. so that B. no matter how C. as long as D. except that 二．填空题 11. In the global economy, a new drug for cancer, ______ it is discovered, will create many economic possibilities around the world. 12. One can always manage to do more things, ____ full one’s schedule is in life. 13.________ great difficulties we are faced with, we’ll never give up. 14. ________ great the difficulties are, we’ll never give up. 15. ______ we have enough evidence, we can't win the case. 16. If _____ to look after luggage for someone else, inform the police at once. (ask) 17.____________ the weather is like tomorrow, I will set out for Hongkong. 18. Many of them turned a deaf ear to his advice ___________ they know it to be valuable. 19. Much ______ I admire David as a poet, I don’t like him as a man. 20. In time of serious accidents, ______ we know some basic things about first aid, we can save lives. 三．改错题 21、It won’t matter even he refuses. 22. Though the work was difficult, but we managed to finish it in time. 23. I’m not going to talk on the point any further, though it is neither important nor very interesting. 24. You will be late if you leave immediately. 25. Take an umbrella with you in case of it should rain.
If引导条件状语从句的详细用法解答
If引导条件状语从句的详细用法解答 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/can If 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/should 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。 4．if从句用一般现在时，主句用一般现在时 If you heat ice it turns to water. (也可用will turn)如果把冰加热，它就会化成水。5．if从句用现在进行时，主句用一般将来时 If you are looking for Peter you’ll find him upstairs. 如果你是在找彼得，上楼就会找到他。 6．if从句用现在完成时，主句用一般将来时 If you have finished dinner I’ll ask the waiter for the bill. 如果你吃完了，我就叫服务生来算账 注意： 学习" if " 引导的条件状语从句的用法,现在总结一下: if 条件句不一般,几个要点记心间; 条件句,放在前,逗号要放句中间。 条件句表可能，主句多用将来时； 条件句表事实，主句常用现在时。
if引导的条件状语从句
语法10单元语法再现梁老师组稿2017-12-31 一、观察下面的句子 If you go to the party, you will have a great time. If you do , you will be late. If you do,you will be sorry. If they have it today, half the class won’t come. If we ask people to bring food, they will just bring potato chips and chocolate. 以上几个句子中“if”有相同的含义“如果”，引导条件状语从句逗号后面的句子是主句。整个连起来的大句子叫主从复合句。 注意主句和从句的时态有什么特点。 总结：If引导的条件状语从句用一般现在时，主句用一般将来时。 简称“主将从现” 练习：（1）If you ______(come)here, you ___________(be) happy. (2) If it _________(rain) tomorrow, we__________(not, go) to the park. (3) If he _________(come) here, I ___________(call) you. (4) If it ___________(not rain), we _________(have) a picnic(野餐). (5) If we do that, more people _________(want) to play the games. 页脚内容1
条件状语从句
初中英语――条件状语从句 一．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/can If 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/should 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。4．if从句用一般现在时，主句用一般现在时 If you heat ice, it turns to water. (也可用will turn)如果把冰加热，它就会化成水。 5．if从句用现在进行时，主句用一般将来时 If you are looking for Peter, you’ll find him upstairs. 如果你是在找彼得，上楼就会找到他。6．if从句用现在完成时，主句用一般将来时 If you have finished dinner, I’ll ask the waiter for the bill. 如果你吃完了，我就叫服务生来算账注意： 学习" if " 引导的条件状语从句的用法,现在总结一下: if 条件句不一般,几个要点记心间; 条件句,放在前,逗号要放句中间。 条件句表可能，主句多用将来时； 条件句表事实，主句常用现在时。 在if 引导的条件状语从句中，如果从句谈论的是一个有可能发生的事实及其产生的相关的结果，主句用一般将来时态，从句用一般现在时态。如： We can walk there if we can't find a bus. If it rains tomorrow, we will not go to the zoo. What will you do if you find a panda in danger? 如果if 条件句谈论的是重复发生和预示要发生的情景和事件，则主从句大多用一般现在时态。如： If bears are in danger, they attack people. 在if 引导的条件状语从句中，if 和条件句位置灵活，可直接放在主句后面，若if 条件句放句首，从句后面要加逗号，和主句隔开。还要注意前后时态一致原则
初中英语——If引导的条件状语从句
初中英语――if引导的条件状语从句 在主从复合句中修饰主句中的动词、形容词、副词等的从句叫做状语从句，状语从句一般可分为时间状语从句、地点状语从句、原因状语从句、目的状语从句、结果状语从句、条件状语从句、让步状语从句、比较状语从句和方式状语从句九种。 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。 Father told me if i worked hard he would buy me a gift. 爸爸告诉我，如果我努力学习，他会给我买一份礼物。
高二必修五重点难点——时间、条件和让步状语从句
Section ⅡGrammar 时间、条件和让步状语从句 时间、条件和让步状语从句在高考中约占3分，考查形式主要有单选、完型填空、语篇填空和改错，主要考察这三种从句中的引导词、谓语动词。 幻灯片3 一、时间状语从句 1．no sooner...than与hardly...when 都表示主句与从句的动作相继发生，意为“一……就……，刚刚……就”，主句动词用过去完成时。如no sooner，hardly位于句首时，主句用倒装形式。 He had hardly gone to bed when the doorbell rang. ＝Hardly had he gone to bed when the doorbell rang. 他刚睡下门铃就响了。 No sooner had he got off the train than his daughter ran towards him. 他刚下火车，他女儿就向他跑了过来。 幻灯片4 2．as soon as，the moment，immediately 引导的从句表示从句动作一发生，主句动作随即发生，常译为“一……就”。名词词组the second，the minute，the moment，every time，any time，next time，the first/last time，the day/week/month等亦可作连词，引导时间状语从句。 They told me about it as soon as/immediately/the moment they got the message.他们一听到口信就把消息告诉了我。 Every time he walked by the lake，he thought of his childhood life.每当他走过那个湖时，就会想起童年的生活。 注意：immediately可用做连词也可用做副词。 幻灯片5 3．till和until 词义是“直到……，一直……为止”，表示一个动作持续到某一时刻或某一动作发生为止，在句首只能用until。在肯定句中，主句中要用延续性动词；在否定句中，可以用非延续性动词。 She stood there till/until he had passed out of sight. 她站在那里看着，直到望不见他的身影。 Until they had finished the work，they did not go home. ＝Not until they had finished the work did they go home. 直到工作完成了他们才回家。 幻灯片6 注意：(1)在not...until结构中not until位于句首时主句部分倒装。在强调句中，强调until引导时间状语时，常把not提前，构成It isn’t/wasn’t until...that...。(2)not...until和not...before意思相同，表示“直到……才，在……以前不”。 幻灯片7
总结好的：if引导的条件状语从句
if引导的条件状语从句 if 1) 用法： (1)条件状语从句通常由连词if引导，意为“如果、假如”，主句不能用be going to表示将来，而应该用shall，will。 If you leave now, you are never going to regret it. (错误) If you leave now, you will never regret it. (正确) (2)if “如果”，引导条件状语从句，主句用一般将来时，从句则用一般现在时，如： If it rains tomorrow, I shan’t climb the hills. (3)另外，主句是祈使句或含有情态动词，从句也用一般现在时。如： Please call me if he comes next Sunday. Can you call the policeman if you are in the trouble. 注意宾语从句中的if与条件状语从句if的区别。宾语从句中的if“是否”相当于whether，引导宾语从句，时态需根据语境确定。如果主句用一般现在时，从句可以根据具体情况选用时态，如果主句用一般过去时，从句必须用过去式的某种形式。 I don't know if it will rain tomorrow. 我不知道明天是否会下雨。 Our teacher said there was going to be a football match the next month.我们说下月将有场足球比赛。 【边学边做】用括号内所给词的正确形式填空。 1. What will you buy if you ________（have）a lot of money? 2. If it ________（not snow）tomorrow, we will feel unhappy. 3. You mustn’t go to school if you ________（be）still in bed. 4. If he _______（be）at home at that time, he would know it. 5. Please show me the way if you ________（know）it. 6. You will hurt your teeth if you ________（eat）too much candy. 7. If you gave me a toy car, I _________（be）very happy. 8. I would get the prize if I _________（work）hard. 9．If she ______ (finish ) work early ,she ______(go) home. 10．If the weather______（be）fine，we_______(go)for a walk .
If 引导的条件状语从句
If 引导的条件状语从句 If 引导的条件状语从句遵循主过从过、主将从现的原则。 主将从现（主情从现、主祈从现） If it rains tomorrow,I won’t climb the hills. If it doesn’t rain tomorrow,I will go to the countryside with my friends. If 引导的条件状语从句 If 引导的条件状语从句遵循主过从过、主将从现的原则。 主将从现（主情从现、主祈从现） If you will help me,I'll finish it on time. We may go out if it's fine tomorrow. If you finish your homework,you can watch TV. Please call me if you go shopping next Sunday. If I go there，I'll take her some flowers. We'll stay at home if it rains tomorrow. Please call me if he’s at home. If you work harder,you’ll pass the exam. She will visit her grandpa if she has time tomorrow. We’ll take a taxi to the city if the train doesn’t arrive on time. The teacher will be angry if he is late. If引导的条件状语从句与unless引导的条件状语从句的转换 If+否定形式=unless+肯定形式
初中英语——If引导的条件状语从句(整理版)
在句子中做条件状语的从句称为条件状语从句。引导条件状语从句的连接词有：if ,unless,as/so long as，once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. 如果没有水会怎样？ 2.unless引导的条件状语从句You will fail in English unless you work hard. 3.as /so long as引导的条件状语从句So long as you're happy,i will be happy. 4.once引导的条件状语从句Once you begin,never stop. 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。Father told me if i worked hard he would buy me a gift. if 条件状语从句的时态练习 二、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. If 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. If Mr Green ___________(say) I am hard- working, my parents _________( feel) glad. 11.I ____________(go) to the beach if it________________ ( not rain) this week. 12. __________they __________( 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. 15.如果他到的晚了会发生什么事情？What _______________ if he _____________ late? 16. 如果努力学习，你就会取得好成绩。 If you__________ _________, you ___________ good _____________. 17. 他如果看电视太久了，他的父母会不高兴。 If he _________ TV too much, his parents __________ __________ unhappy. 18. 如果我们为他组织生日聚会，大家都会来的。 Everyone ________________ if we _____________ a birthday party __________ him. 19. 如果明天不下雨，我会和你一起去公园的。 If it __________ __________ tomorrow, I ______________ go to the park _________ you.
高考英语被动语态、条件状语从句和让步状语从句导学案
被动语态、条件状语从句和让步状语从句 李仕才 课程目标 一、学习目标 1. 条件状语从句及其连词的用法。 2. 让步状语从句及其连词的用法。 3. 被动语态。 二、重点、难点 重点：条件状语从句、让步状语从句及被动语态。 难点：让步状语从句和名词性从句的区别。 三、考情分析 这三种语法是高考考查的重点语法，历年考题中占有重要的地位，一般能在单选中占3-4分；在完形填空中也能占2-3分；我们复习时要特别注意这几种语法及其做题技巧，认真研究近几年的高考题。 知识梳理 一、条件状语从句 【教材原句】 If you say the word “communication”, most people think of words and sentences. 如果你说单词“交流”，大部分人会想到单词和句式。 If our right hand is busy greeting someone, it cannot be holding a weapon. 如果我们的右手忙着问候别人，它就不可能握有武器。 考点1引导条件状语从句的从属连词 【用法】 连接词主要有if, unless, as/so long as, on condition that, provided, suppose, supposing 等。 【例句】 You can leave now if you like. 如果你愿意现在就可以走了。 As long as it doesn’t rain we can go.
只要不下雨，我们就可以去。 In case I forget, please remind me about it. 万一我忘记，请提醒我一下。 I will come on condition (that) she is invited too. 如果邀请她来, 那我就来。 He may go with us provided [providing] he arrives in time. 他若及时到达，就可以和我们一起走。 【考题链接】 they decide which college to go to, students should research the admission procedures. A. As B. While C. Until D. Once 答案：D 解题思路：句意：一旦他们决定去哪个大学，学生就应该搜索入学手续。once 一旦，根据句意选择D。 考点2条件状语从句的时态 【用法】 当主句为将来时态或具有将来意义时，条件状语从句通常要用一般现在时表示将来意义，而不能直接使用将来时态。 【例句】 Let’s go out for a walk unless you are too tired. 如果你不是太累的话，让我们出去散步。 I’ll stay at home if it rains tomorrow. 要是明天下雨，我就呆在家里。 【考题链接】 We will be losing money this year unless that new economic plan of yours _______ well. A. is working B. works C. will be working D. worked 答案：B 解题思路：句意：如果你的那个新经济计划效果不好的话，我们今年会失去很多钱。在条件状语从句中，如果主句用一般将来时态，那么从句用一般现在时态表示将来意义。 考点3if 引导的条件句有真实条件句和非真实条件句两种 【用法】 真实条件句表示现实情况中可能实现的情况。非真实条件句也叫虚拟条件句，表示与现实情况相反的假设情况。 【例句】
If引导的两种从句(宾语从句和条件状语从句)
重点、难点 1. 含有if引导的条件状语从句的复合句中主从句的时态。 2. If引导的宾语从句与条件状语从句的区别。 考情分析 通常在单项选择、完形填空或补全、完成句子等题型中考查，分值约3—4分。 知能提升 （一）知识讲解 【认知讲解】 I. if引导的宾语从句 if 引导宾语从句时，意思为：是否，从句的时态通常要和主句保持一致。 【例句】 I want to know if he lives there. 我想知道他是否住在那儿。 He asked me if I could help him. 他问我是否能帮他。 【考查点】if、whether引导的宾语从句的区别 1. if或whether引导宾语从句时，作“是否”讲，常放在动词ask、see、say、know和find out等后面。一般情况下，两者常可换用，在口语中多用if。 【例句】 Nobody knows whether / if it will rain tomorrow. 没有人知道明天是否下雨。 Lucy asked whether / if they had a cotton sweater. 露西问他们是否有棉制的毛衣。 2. if或whether引导宾语从句时，要注意三个方面，即连词、语序和时态。 if或whether既不能和that 或其他连词（副词）同时使用，也不能省略。 【例句】 我不知道他今天是否会来。 [误] I don’t know that if(whether) he will come here today. [正] I don’t know if(whether) he will come here today. 他走过来看看猫是否出了毛病。 [误] He came to see what if (whether) there was anything wrong with his cat . [正] He came to see if (whether) there was anything wrong with his cat . if或whether引导宾语从句时，虽具有疑问的意义，但其从句应用陈述句的语序。 【例句】 Did you know the way to the hospital The old woman asked me. The old woman asked me if / whether I knew the way to the hospital. 老妇人问我是否知道去医院的路。 if或whether引导的宾语从句应和主句的时态保持一致。即主句为一般现在时，从句用任一种时态；主句为一般过去时，从句则用过去时中的任一种时态。 【例句】 I don’t know if (whether) he has come here. 我不知道他是否来过这儿。
初中英语If引导的条件状语从句
初中英语――if引导的条件状语从句 在if 引导的条件状语从句中，if 和条件句位置灵活，可直接放在主句后面，若if 条件句放句首，从句后面要加逗号，和主句隔开。还要注意前后时态一致原则.引导条件状语从句的连接词主要有：if(如果）、unless（除非）或as long as （只要）等。unless在意思上等于if...not。 一、条件状语从句用法 1、引导条件状语从句最常用的连词是if,由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。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。 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。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。 2、unless = if...not.除非,若不,除非在……的时候 例如：Let's go out for a walk unless you are too tired. =If you are not too tired, let's go out for a walk. Unless it rains, the game will be played. 除非下雨,比赛将照常进行。 二、时态问题 在条件状语从句中，要注意“主将从现”的规定，即主句用一般将来时，从句用一般现在时表示将来时。例句： I will come to see you if I have time. 我有时间，我就来看你。 三如果if 条件句谈论的是重复发生和预示要发生的情景和事件，则主从句大多用一般现在时态。如： If bears are in danger ,they attack people. 误区提醒 if 既可以引导条件状语从句，表示“如果”，也可以引导宾语从句，表达“是否”。辨别它在这两种从句中的时态是我们经常容易出错的地方。另外，if 和unless的用法也需注意。 典型例题：----I wonder if your wife to the party. ----If your wife _________, so will mine。. A. will go，go B. will go, goes C.goes, will go D. will go, will go 解析：第一句中if表示“是否”，引导宾语从句，用将来时will go；第二句“如果你的妻子去，我的妻子也去”，if引导条件状语从句，用一般现在时表示将来时。your wife，单三人称主语，所以用goes 。