if引导的条件状语从句和虚拟语气的区别word版本
1.if引导的条件状语从句和虚拟语气的区别
if引导的条件状语从句所引导的是原因状语，可以是现实生活中已经出现的真实事件或有可能出现的事情，发生的可能性较大。而虚拟语气所引导的往往是非真实的，对于过去，现在或将来的虚拟或推断，发生的可能性较小，或已经不可能发生了
可以从2个角度去区分：
1。时态
A，由if引导的条件状语从句通常都是主句为一般将来时，从句为一般现在时。
B，而在虚拟语气中，时态都是有很多，往往都是根据句子的含义判断，究竟是与现在，过去还是将来的事实相反。
2。真实与非真实
A，由if引导的条件状语从句一般都是真实的，只要所谓的条件成立，一定会成为事实
B，但虚拟语气并非如此，if，既然是虚拟，就一定是非真实的，可以根据句意判断其是...
条件状语从句
连接词主要有 if, unless, as/so long as, on condition that 等。if 引导的条件句有真实条件句和非真实条件句两种。unless = if not. 例如：
Let's go out for a walk unless you are too tired. 如果不太累，我们去散散步。
If you are not too tied, let's go out for a walk.
You will be late ___ you leave immediately.
A. unless
B. until
C. if
D. or
答案A。句意：除非你立即走，否则你就回迟到的。可转化为 If you don't leave immediately, you will be late。B、D句意不对，or表转折，句子如为 You leave immediately or you will be late.
虚拟语气
1）虚拟语气用来表示说话人的主观愿望或假想，所说的是一个条件，不一定是事实，或与事实相反。虚拟语气在条件句中应用比较多。
2）条件句可分为两类，一类为真实条件句，一类为非真实条件句。非真实条件句表示的是假设的或实际可能性不大的情况，故采用虚拟语气。
真实条件句用于陈述语气，假设的情况有可能发生。
一般现在时
shall/will + 动词原形
祈使句情态动词一般现在时
例如：If he comes, he will bring his violin. 如果他来，会带小提琴来的。
The volleyball match will be put off if it ___.
A. will rain
B. rains
C. rained
D. is rained
答案B。真实条件句主句为将来时，从句用一般现在时。
注意：
1）在真实条件句中，主句不能用be going to表示将来，该用shall, will. （错） If you leave now, you are never going to regret it. （对） If you leave now, you will never regret it.
2）表示真理时，主句谓语动词不用shall （will） +动词原形，而直接用一般现在时的动词形式。
非真实条件句
1）虚拟语气可以表示过去，现在和将来的情况，时态的基本特点是时态往后推移。
a. 与现在事实相反的假设
一般过去时（be用were）should（would）等 +动词原形
例如：If they were here, they would help you. 如果他们在这儿，会帮助你的。
含义：They are not here, they can’t help you.
b. 与过去事实相反的假设
过去完成时
should（would）等+ have+ 过去分词
例如：If he had come yesterday, I should / would have told him about it.如果他昨天来的话，我会把这件事告诉他的。
含义：He did not come yesterday, so I did not tell him about it.
c. 表示对将来不大可能发生的事情的假想
一般过去时
should/would等 + 动词原形
were+ 不定式
should+ 动词原形
例如：If you succeeded, everything would be all right. 如果你将来成功了，一切都会好的。
If you should succeed, everything would be all right.
If you were to succeed, everything would be all right.
含义：You are not likely to succeed, everything will be what it is now.
if引导虚拟语气的教学设计
If引导非真实条件句（虚拟语气）语法教学设计 汉中市宁强县天津高级中学外语组：邱怡 一、?高中英语课程标准？分析： 虚拟语气这一语法项目是各类英语考试中心测试的重点之一，在高考题型中都有可能会涉及到，是高中阶段英语学习的一个重点和难点，也是高考英语常考的一个考点，掌握好虚拟语气对于语言理解和运用也具有重要的意义。 1.什么是虚拟语气即虚拟语气的概念； 2.掌握if引导虚拟语气的语法规则； 二、学情分析： 我所在的学校是一所山区高中，学生英语学习习惯差，语法知识混乱。很多学生学习英语困难，基础知识不扎实，在实际做题时常常无从下手，不能灵活运用。 三、教学目标： 1.知识与技能目标：掌握if引导虚拟语气语法的基本规则；能解决有关虚拟语气的习题。 2.过程与方法目标：教师讲解引导，举例并做练习 3.情感和价值目标：通过教师主动性和创造性的发挥，激发学生的学习兴趣，体验成就感。 四、教学重难点： 1.教学重点：了解和掌握if引导虚拟语气语法项目的基本规则 2.教学难点：能运用语法规则去完成各种练习，并在实际语言活动中去灵活应用，培养学生的语言运用能力和英语思维。 五、教学和学法方法： 教法讲授法：情景教学法，任务型教学法 六：教学手段： 多媒体辅助教学 七、教学过程： stepl Leadi ng in Show the following questions on the screen ，ask students to answer the questio ns will you do when you finish education you had 100 milli on yua n, what would you do Show a picture from a film which stude nts are familiar with, and list senten ces used subj un ctive mood in the film. （通过这几个问题的讨论，让学生了解虚拟语气的基本概念，引出if非真实条件句） step2 Prese nting Suppose three con diti ons of prese nt, past and future senten ces. First con diti on 1. If I were you, I would seize the cha nee to relax myself. am too busy now. If I had time, I would go shopping with you. Con cludi ng:
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。
if条件句中的虚拟语气讲解
虚拟语气(一) 一、考点聚焦 1、虚拟语气用于条件状语从句中 If I were a boy, I would join the army. If she had time, she should go with you. If h e had taken my advice, he would have succeeded in the competition. If i t were to rain tomorrow, the football match would be put off. If I had time, I would attend the meeting. If he had hurried ,he could have caught the train. If I were to go abroad ,I would go to America 如果我是你，我就会努力学习 If I were you, I would work harder at my lessons. 如果我知道他的电话号码，我就给他打电话了 If I had known his telephone number, I would have called him. 如果明天下雨的话，我们会取消比赛． If it should \were to rain, we would call off the match.
使用虚拟条件句要注意的几点： １．当条件状语从句表示的行为和主句表示的行为所发生的时间不一致时，被称为：错综时间条件句“，动词的形式要根据它所表示的时间作出相应的调整． If you had followed my advice , you would be better now. 如果你听我的建议，你现在就会痊愈了． If you had studied hard before, you would be a college student now. 如果你努力学习的话，你现在就会是大学生了． If they had worked hard, they would be very tired now.(从句说的是过去，主句指的是现在) ２．省略句 在条件句中，可省略if，把were ,had, should 提到句首，变为倒装句式．If I were at school again, I would study harder. Were I at school again, I would study harder. If you had come earlier, you would have met him. Had you come earlier, you would have met him. If it should rain tomorrow, we would not go climbing. Should it rain tomorrow, we would not go climbing. Were I a boy, I would join the army. Had he taken my advice, he would have succeeded. Were it not for the expense, I would go to Britain. 2、虚拟语气用于名词性从句 （1）虚拟语气在宾语从句中的运用。 ①“wish + 宾语从句”表示不能实现的愿望，译为“要是……就好了”等。 表现在过去时 表过去过去完成时 表将来would, might, could＋动词原形 I wish it were spring all the year round. I wish I had known the answer. I wish I could fly like a bird. I wish (that) I were a bird. I wish (that) I had seen the film last night. I wish (that) I would\could go.
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
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。
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。
(完整版)if引导的非真实性条件状语从句即虚拟语气
if 引导的非真实性条件状语从句即虚拟语气 通过动词形式的变化来表示说话人对发生的动作或存在的状态所持的态度或看法的动词形式称为语气。.英语中的语气分三种：陈述语气、祈使语气、虚拟语气。虚拟语气表示说话人所说的话不是事实，而是一种祝愿，建议，与事实相反的假设或实际可能性不大的情况等（即非真实的假设）。 If 引导的条件状语从句分为真实和非真实条件句（虚拟条件句）。真实条件句表示在假设的条件下，有可能实现的情况。非真实条件句表示的是假设的或实际可能性不大的情况，故采用虚拟语气。 If he does n’t hurry up, he will miss the bus.( 真实条件状语) If he was free, he asked me to tell stories.（真实条件状语） If I were you, I would go at once.（非真实条件状语从句） If there was no air, people would die.（非真实条件状语从句）1）非真实条件句中虚拟语气的基本形式。 假设类型条件从句的动词结果主句的动词 与现在事实相反动词过去式（be只用were）would/should/could/might + 动词原形 与过去事实相反had+过去分词would/should/could/might + have + 过去分词 与将来事实相反动词过去式/(should/were to)+动词原形would/should/could/might + 动词原形
①与现在事实相反 If I had time, I would go for a walk. 如果我有时间，我就会去散步。(实际情况：我现在没有时间，也不会去散步。) If I were you, I would take an umbrella. 假如我是你的话，我会带上雨伞。(事实上我不可能是你。) I would say no if someone asked me to be in a movie. 假如有人请我当电影演员，我会表示拒绝。(事实上现虚拟语气专项练习 1．Were it not for the snowy weather, we __________all right. A. would be B. would have been C. were D. may be 2. ________more careful, his ship would not have sunk. A. If the captain were B. Had the captain been C. Should the captain be D. If the captain would have been 3. If he _________ me tomorrow, I would let him know. A. should call B. should not have been able C. were not able D. are not able 4.If you asked your father, you ______________ permission. A. may get B. might get C. should have called D. maybe get
高考if条件句虚拟语气
高考虚拟语气试题 1. ____ to the doctor right away, he might have been alive. A. If he went B. Were he gone C. Should he have gone D. Had he gone 2. If you were older, I ____ you to go there yesterday. A. will allow B. should allow C. would have allowed D. had allowed 3. If we ____ here ten minutes earlier, we ___ the bus. A. arrived/would catch B. arrived/would have caught C. had arrived/had caught D. had arrived/would have caught 4. If I ___ more time, I would have gone with him. A. had B. had had C. have had D. would have 5. If he had not gone out in the storm _____. A. he will be alive now B. he would be alive now C. he would have been alive now 6. If it ___ tomorrow, what would we do? A. rains B. were to rain C. would rain D. rain 7. If only I _____ how to operate an electronic computer as you do. A. had known B. would know C. should k now D. knew 8. If it ___ rain, we ___ get wet. A. is to, should B. were to, would C. were going to, would D. was going to, should 9. If he ___ to the teacher attentively, he ___ the answer to the problem now. A. had lis tened, would have known B. listened, would know C. listened, would have known D. had listened, would know 10. ---- I thought you would come back tomorrow. ---- I would if I ___ to attend a meeting. A. don’t have B. didn’t have C. will not have D. would not have 11. If I had hurried, I ___ the train. A. would catch B. could catch C. would have caught D. had caught 12. If I had known that, I ___ so. A. wouldn’t do B. wouldn’t have done C. won’t do D. have not done 13. If I ___ you, I wouldn’t return the call. A. be B. am C. was D. we re 14. If the doctor had been available, the child ___. 教育是一项良心工程 1
if条件状语从句中虚拟语气
if条件状语从句中的虚拟语气 一、if条件状语从句中虚拟语气的判断判断是真实条件句还是非真实条件句。 只有在非真实条件句中才使用虚拟语气。通过句子意思，看假设的条件是否能够实现， 能够实现是真实条件句，不能使用虚拟语气； 假设的条件不能实现则是非真实条件句，要用虚拟语气。 1. “后退一步法”后退一步法是指在准确地判断了该句与哪一事实相反后，按虚拟语气的后退一步法处理从句谓语动词的时态。即：在非真实条件状语从句中，谓语动词按正常情况“后退一步”。也就是： ①与过去事实相反，在从句中用过去完成时形式表示。 ②与现在事实相反，在从句中用过去一般时形式表示。 ③与将来事实可能相反，在从句中用过去将来时形式表示。主句中则用情态动词would, should, could 等加一个与从句一致的动词形式。 例：⑴、If I had come her yesterday, I would have seen him. ⑵、If I were a teacher, I would be strict with my students. ⑶、If it should snow tomorrow, they couldn't go out. 2、注意事项： ①if条件句中如有were, should, had，可以省去if，并使用倒装语序。 ②在现代英语中if条件状与从句中的谓语动词如果是be其过去形式一般用were。 二、虚拟语气在if 引导的条件句中的用法： 1. If it weren’t for your help, we would get into trouble. 如果没有你们的帮助，我们就会陷入困境。（而事实上得到了你们的帮助） 2.If the weather were fine, I would go there. 如果天气好，我去那儿。（事实天气不好） 3.If I were you, I would read it again. 如果我是你的话，我再读一遍。（事实上我不是你） 4.If time permitted, I would write it again. 如果时间允许的话，我再写一遍。（事实上时间不允许） 5.If it weren’t snowing, we wouldn’t stay in the house. 要是现在不下雪的话，我们就不会待在屋里。（事实上现在下雪） 6.What would I do if I were in your place?要是我处于你地位我会怎么办？（事实上我不在你的位置上） 7.If he hurried, he could catch the first bus. 他要是快点能够赶上头班公共汽车。（可是他不着急） 8. If I were you, I should buy it. (从句用过去式动词were，主句用动词原形buy) 9. If I had time, I would study French. (如果有时间，我会学习法文。)（从句用过去式动词had，主句用动词原形study） 10. If she knew English, she would not ask me for help. (如果她懂英文，她就不必要我帮了。)(从句用过去式动词knew, 主句用动词原形ask) 注意：如果动作在进行中，主句要用："主语+ would be + 进行式动词+ ……" 14. If they were here, he would be speaking to them now. (从句用过去式动词were, 主句用would be speaking)
if条件状语从句专练
If条件状语从句专练 1. If I ___(go) to the party, they ___(be) upset. 2. If I ___(take) a taxi, it ___(be) too expensive. 3. If she ___(finish) work early, she can go home. 4. If the weather is fine, we ____(go) for a walk. 5. If I ___(have) time tonight, I will finish the book. 6. If it ___(rain) next Sunday, we won`t be able to plant trees. 7. If she ___(arrive) home, she will phone
me. 8. Unless you speak to him first, she ___(not speak) to you. 9. If he ___ (call) to you, tell him I will ring back. 10. I don`t know if it ___(rain) tomorrow. 11. Have a rest if you ___(be) tired. 12. Don`t come unless I ___(call) you. 13. I don`t know if he ___(come) tomorrow, but if he __(come), I`ll let you know. 宾语从句与状语从句混合 1. ——Helen, do you know if Martin
(完整版)if引导的条件句中的虚拟语气
if引导的条件句中的虚拟语气 虚拟语气表示一种不能实现的假设。该语法主要用于if条件状语从句。 一、if引导的条件状语从句的分类及虚拟条件句的判断 1、可以把条件句分为两类： 1).真实条件句（Sentences of Real Condition）：凡是假设的情况发生性可能很大，就是真实条件句。例如： ⑴、If I have time , I will help you with this work.如果我有时间会帮助你做此工作的。 (2)、If time permits, we'll go fishing together.(如果有时间的话，我们就一起去钓鱼。） 2).虚拟条件句（Sentences of Unreal Condition）：当假设是不大可能实现时，就是虚拟条件句。例如： ⑴、If I were you , I would have attended the meeting. 如果我是你的话，就去参加会议了。 ⑵、If he had come here yesterday, he would have seen his ol d friend.假如他昨天来这儿的话，就会看见他的老朋友。 ⑴、If it had rained yesterday, we would have stayed at home.（如果昨天下雨的话，我们就会留在家里。） 2、.if条件状语从句中虚拟语气的判断 判断是真实条件句还是非真实条件句。只有在非真实条件句中才使用虚拟语气。通过句子意思，看假设的条件是否能够实现，能
够实现是真实条件句，不能使用虚拟语气；假设的条件不能实现则是非真实条件句，要用虚拟语气。 判断这个假设是与哪个事实相反。通常有三种情况：①与过去事实相反。②与现在事实相反。③与将来事实可能相反。 3、“后退一步法” 后退一步法是指在准确地判断了该句与哪一事实相反后，按虚拟语气的后退一步法处理从句谓语动词的时态。即：在非真实条件状语从句中，谓语动词按正常情况“后退一步”。也就是： ①与过去事实相反，在从句中用过去完成时形式表示。 ②与现在事实相反，在从句中用过去一般时形式表示。 ③与将来事实可能相反，在从句中用过去将来时形式表示。 主句中则用情态动词would, should, could 等加一个与从句一致的动词形式。例： ⑴、If I had come her yesterday, I would have seen him. ⑵、If I were a teacher, I would be strict with my students. ⑶、If it should snow tomorrow, they couldn't go out. 4、注意事项 ①if条件句中如有were, should, had，可以省去if，并使用倒装语序。 ②在现代英语中if条件状与从句中的谓语动词如果是be其过去形式一般用were。
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
if引导的条件状语从句-与专题练习
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。如： If you ask me ,I will answer you． If it rains tomorrow, I will stay at home. I will stay at home if it rains tomorrow. 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 in university，I would …． If I had enough money ,I would buy a car. 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． 2.if从句用一般现在时，主句用may/might/can/must If the fog gets thicker the plane may/might be diverted. 3.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) 4. 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. 5.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.
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 引导的虚拟语气
If 引导的虚拟语气 虚拟语气是一种特殊的动词形式，用来表示说话人所说的并不是事实，而是一种假设，愿望，怀疑或推测。判断是真实条件句还是非真实条件句，只有在非真实条件句中才能使用虚拟语气。通过句子的意思，看假设的条件是否能够实现，能够实现的是真实条件句，不能使用虚拟语气。假设的条件不能实现则是非真实条件句，要用虚拟语气。判断这个假设是与那个事实相反，通常有三种情况1与过去事实相反2与现在事实相反3与将来事实相反 最基本的虚拟语气句型 1虚拟现在时表示与现在事实相反的假设，其if从句的谓语形式用动词的过去式(be一般用were)，主句用would/should/could/might+动词原形。 例句:If I place were alike ,there would be little need for geographers. 如果各个地方都一样，就读需要地理学家了。 If I were you,I should do that.如果我是你，我就那么做。 2虚拟过去时是表示与过去事实相反的假设，if从句的谓语形式用过去完成时，即had+过去分词。主句用would/should/could/might+have+过去分词。 例句： If he had know your address yesterday,he would have telephoned you 如果昨天他知道你的地址，那他就打给你了。 If he had been there last night,it wouldn’thave happened. 如果他昨晚在那里，这事就不会发生。 If you had come a little earlier,you could have met him. 如果你早点来，你就能遇见他。 3虚拟将来时是表示对将来实现的可能性很小或不确定的假设。If从句的谓语形式用一般过去式或用were to/`should+动词原形，主句用would/should/could/might+动词原形。 If anyone set me free,I would make him very rich. 如果有人把我放出来，我会使他富有。 If it should rain the crops would be saved. 如果有雨下，庄家就有可能救活。 If it were to snow tomorrow,they wouldn’t go for an outing. 如果明天下雪，他们就不外出游玩。
if引导的条件状语从句-虚拟语气
虚拟语气是一项语法难点，为了让学员们便于理解与记忆，我们把虚拟语气分成三大块来讨论： 1．名词从句中的虚拟语气标志词+should+动词原形 2．条件从句中的虚拟语气①三种基本态②倒装虚拟句③混时虚拟句④含蓄虚拟句⑤跳层虚拟句 3．其它情形中的虚拟语气（wish/would rather/It’s high time…/If only…/lest） 一．三种基本形态（1） 表虚拟的时间if从句谓语形式主句谓语形式 现在：did / were would (should, might, could)+do 过去：had done/ had been would (should/might/could)+have done(been) 将来：were to/ should+do would (should, might, could)+do 三种基本形态（2）（这是基础，建议牢记下面的例句，争取能脱口而出） 与现在事实相反：If I had enough money, I would buy a book. 与过去事实相反：If I had had enough money, I would have bought a book. 与将来事实相反：If I were to have enough money, I would buy a book. If I should have enough money, I would buy a book. 二、倒装虚拟句（只能与过去/将来事实相反，省去if，只有三种倒装形式）Had I had enough money, I would have bought a book. Were I to have enough money, I would buy a book. Should I have enough money, I would buy a book. 三、混合时间虚拟语气（主要是抓住时间状语） (对过去事实虚拟+对现在事实虚拟) If I had studied English at school, I could read the English novel now. (对现在事实虚拟+对过去事实虚拟) If she were not so careless, she wouldn’t have made such a mistake. 四、含蓄虚拟句（在四级考试中目前还未出现此考点，但在阅读中常见） 3. 虚拟语气用在主语从句中。在句型“It is important (necessary, strange, natural等) that...” 中，that 后面的从句中的谓语动词用(should) + 动词原形。It's necessary that we should have a walk now. 我们现在有必要出去散散步。What would I have done without you? But for their help, I would not have finished the task. But that the doctor arrived on time that day, they would have been dead. Given more time, I would have been able to finish the test.