if条件句中的时态应用
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If引导的条件状语从句一、If引导的条件状语从句的结构If+主语+谓语+其它,主语+谓语+其它.=主语+谓语+其它+if+主语+谓语+其它.注:①有if 的是从句,另一个是主句② if 从句在前有逗号,if从句在后无逗号eg.If he runs, he will arrive there in time .=He will arrive there in time if he runs .如果他跑,她将会准时到达.二、if条件句主句和从句的时态,if译为如果1.主句用一般将来时(will+ V-原),if 从句用一般现在时(be用is/am /are ,实义动词用V-原/V-三单), 即主将从现注:①当主语为I ,you, we, they ,复数名词,以及由and连接的两个并列成分等时,实义动词用V-原②当主语为he ,she ,it ,that ,单个人名,单数名词等时,用V-三单)eg .If it is (be) rainy , we will stay(stay) at home .If she studies (study ) hard , she will get (get) good grades .2.若主句中含有情态动词(can/may/ must/may/might/should )时,主句为情态动词+ V-原,if从句用一般现在时eg .We can will go(go) out if it stops (stop ) raining .eg.If you want (want) to get good grades ,you should study (study)hard.3.若主句为肯定祈使句或否定祈使句时,if从句用一般现在时注:以V-原开头的句子是肯定祈使句,否定祈使句在V-原前加Don’teg. Eat (eat) them if you are (be) hungry .eg. Don’t go (not go)to play football if she doesn’t finish (not finish)your homework .拓展:if 还可引导宾语从句,译为“是否”If 引导宾语从句时,时态需根据语境确定,如果主句是一般现在时,从句可以根据具体情况选用时态,如果主句是一般过去时,从句必须跟过去时相关( )1.----Mike wants to know if _________ a picnic tomorrow .----- Yes . But if it _________ , We will visit the museum .A. will you have , will rainB. you will have , will rainC. you will have ,rainsD. will you have , rain( )2.We are not sure if it ____ tomorrow .If it ____ , our sports meeting will be put off .A. will rain , rainsB. rains , will rainC. will rain ; will rain ( )3. ---Can you guess if Mike _______ swimming this afternoon ?---I think he will go with us if he _______ fine .A. will go ,isB. will go ,will beC. goes , isD. goes ,will be答案解析:1.迈克想知道是否你们明天将去野营,if译为是否,引导宾语从句,时态根据语境而定,句末有tomorrow , 所以要用将来时。
if条件状语从句及其时态的用法*概念引入英国前首相撒切尔夫人〔Margaret Thatcher〕曾用if条件句对男人和女人进行评价:In politics, if you want someone to make a speech, ask a man; if you want something done, ask a woman. 在政治领域,如果你想要有人发表演说,那就找男士去;而如果你想真正把事情解决,那就找女士。
*用法讲解一、概念连词if的意思是“如果〞,它引导的句子表示某事发生所需要的条件,即“在……条件下某事才能发生〞,在句子中充当状语,因此我们称之为条件状语从句。
在复合句中连词if 引导的句子为从句,被修饰的句子为主句。
从句可以放在主句后,也可以放在主句前,从句放在主句前时,应用逗号将它与主句隔开。
例如:We’ll go to the Great Wall if it doesn’t rain tomorrow.= If it doesn’t rain tomorrow, we’ll go to the Great Wall. 如果明天不下雨,我们就去长城。
二、用法1. 条件状语从句通常由连词if引导,意为“如果,假设〞,主句不能用be going to 表示将来,而应该用shall或will。
例如:If I’m free tomorrow, I’ll go with you. 如果我明天有空,我将会和你一起去。
2. if引导的条件状语从句,主句用一般将来时,从句那么用一般现在时,即“主将从现〞。
例如:If it is sunny tomorrow, I’ll climb the hill. 如果明天天气晴朗,我将去爬山。
3. 正确区分if引导的条件状语从句和if引导的宾语从句。
在条件状语从句中,if表示“如果〞;而在宾语从句中,if表示“是否〞。
可以用下面的方法区分:1) 从句前置法:if引导的条件状语从句,可以放在主句之前并用逗号隔开,也可放在主句之后;而if引导的宾语从句只能放在主句之后。
if引导的条件状语从句总结(精)if引导的四种条件状语从句一、零条件句/绝对真实条件句(Zero Conditional)零条件句,又叫绝对真实条件句,用于阐述事实。
用来表达在该条件下,结果一定会如此(如规则,客观规律、真理等)。
结构是:If+主语+do/does,主语+do/does。
其从句和主句的谓语动词通常为一般现在时。
二、第一条件句/相对真实条件句(First Conditional)第一条件句又叫相对真实条件句,谈论将来可能发生的事情,并考虑这件事情的结果。
强调偶然性或一次性的条件,也可以与绝对真实条件句同义。
if从句用一般现在时或其他现在时,表示将来可能发生的事情(条件);主句用一般将来时,表示这件事情的结果。
结构是:If+主语+do/does,主语+will do。
三、第二条件句/现在虚拟条件句(Second Conditional)第二条件句是虚拟条件句的一种,即现在虚拟条件句(Unreal Present),用来表达在现在或将来时间下不太可能或不可能发生的条件,这种条件句还可以用来表示试探性的、委婉的语气(可以理解为不大有自信,所以不太真实的条件)。
结构是:①与将来事实相反的非真实条件句是If+主语+should do/were to do/did,主语+would/should/could/might do;②与现在事实相反的非真实条件句是If+主语+did,主语+would/should/could/might+do。
四、第三条件句/过去虚拟条件句(Third Conditional) 第三条件句是表示与过去事实相反的虚拟语气,是用来表达如果(If)当时那样发生,另外一方面(当时)结果会如何。
通常是指过去的事情,带有一切已经太迟而不能够补救的意思。
结构是:If+主语+had done,主语+would/should/could/ might+have done。
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.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.4.if从句用一般现在时,主句用一般现在时5.if从句用现在进行时,主句用一般将来时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.。
语法专题:条件状语从句(1)if条件句:有可能性结果发生的行动,在这些句子中,动词的时态是不同的,if 引导的条件状语从句中,主句用一般将来时态,从句用一般现在时态(主将从现)If it doesn’t rain(从句), we’ll have a picnic tomorrow(主句).We’ll have a picnic tomorrow, if it doesn’t rain.(if引导的从句可置前可置后)(2)主祈从现(祈使句+if+一般现在时态)Put up your hands if you have any questions to ask. 如果你们有问题问的话,请举手。
当主语是you时,if 引导的条件状语从句可以与”祈使句+and/ or +简单句”进行句型转换。
And 表示句意顺承,or 表示转折,意为”否则”。
Take care , or you will fall off the tree. = If you don’t take care, you’ll fall off the tree. 小心,否则你会从树上掉下来。
(3)主情从现(情态动词+if +一般现在时态)If I get there early, I can see the doctor quickly.(4)句型:will do式be going to do式肯定从句If主语+动词+其他, 主语+will(won’t) do+其他. If主语+动词+其他, 主语+be(be not) going to do+其他.否定从句If主语+be+not+其他, 主语+will(won’t) do+其他. If主语+be+not+其他, 主语+be(be not) going to do+其他.If主语+don't/ doesn't +动词原形+其他, 主语+will(won’t) do+其他. If主语+don't/ doesn't +动词原形+其他, 主语+be(be not) going to do+其他.If the picture is silly, strange and colourful, you will remember it better.If I have time, I am going to visite you .I will go to the park if it doesn’t rain tomorrow . I won't go to the park if it rains tomorrow.专题精讲实战演练题型1:单项选择( ) 1. If the robot ___________ wrong,you can get a new one for free or get all your money back.A. wentB. goesC. would goD. will go ( ) 2. —We’ll go for a picnic if it ___________ on Sunday.—Wish you a lovely weekend.A. rainB. doesn’t rainC. won’t rainD. rains ( ) 3. I’ll do it better if the teacher ___________ me another chance.A. giveB. givesC. gaveD. will give( ) 4. If a polar bear ___________, it ___________ fish from the waterA. will be hungry;catchesB. is hungry;will catchB. is going to be hungry;catches D. is hungry;won’t catch( ) 5. If our government ___________ attention to controlling food safety now, our health ___________ in danger.A. won’t pay; isB. doesn’t pay; isC. won’t pay; will beD. doesn’t pay; will be( ) 6. We will go for a picnic if it___________ tomorrow.A. doesn’t rainB. wasn’t rainyC. won’t rainD. wasn’t raining( ) 7. If the pure water is heated to 100 centigrade degrees, it___________ boil.A. is going toB. willC. wouldD. is to ( ) 8. She will go to America___________ she has much free time and money.A. as long asB. butC. thoughD. although( ) 9. We will go to the West Lake___________ it doesn’t rain heavily tomorrow.A. ifB. unlessC. as long asD. once ( ) 10. I won’t call you, ___________ something unexpected happens.A. unlessB. whetherC. becauseD. While Keys: 1-5 BBBBD 6-10ABAAA题型2:以所给词的正确形式填空1. If he ________ (study) hard, he will get good grades.2. Everyone must wear uniforms. If you don't, they ___________ (let) you in.3. If you stand at the top of the mountain, you _________ (see) the view of the whole city.4. My grandfather will wear a pair of glasses if he__________ (read) newspapers.5. Please turn off the light if you ________ (leave) the classroom.6. We’ll go for a picnic unless it ________(rain) this Sunday.7. Mr Smith ________ (let) you know if he needs help.8. If you walk along the street, you ________ (see) many foreigners.9. If Mary ________ (ask) me for help,I will try my best to help her.10. I don't know if it will snow tomorrow. If it_______ (snow),we'll make snowmen. Keys:1. Studies 2.won’t let 3. will see 4. reads 5.leave6.doesn’t rain7.will let8.will see9. asks 10.snows直击中考题型1:单项选择( ) 1.—I wonder if your wife ________ to the party.—If your wife _________, so will mine.A. will go, goB. will go, goesC. goes, will goD. will go, will go ( ) 2. If he _________ in half an hour, we _________ wait for him.A. won't come, won'tB. won't come, don'tC. doesn't come, won'tD. will come, don't ( ) 3. I will send you an e-mail as soon as I_________ in Canada.A. arriveB. arrivedC. am arrivingD. will arrive( ) 4. 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 ( ) 5. You can’t watch TV ________ you finish your homework.A. beforeB. ifC. whileD. asKeys:1-5:ACAAA。
if主将从现的用法例句一、if主将从现的含义及用法介绍if主将从现是英语中一种虚拟条件句的形式,常用来表达对于可能或想象中的情况下所做出的判断或推测。
该语法结构由“if”引导,并接上主句和从句。
在从句中使用的动词常采用一般现在时态,而在主句中则以模态动词(如“would”、“could”、“might”)+动词原形的形式出现。
这种语法结构广泛应用于日常英语交流和文学作品中,它能够帮助人们表达虚构、不确定和假设等多种意图。
二、 if主将从现的例句解析及说明1. If I had more time, I would travel around the world.(如果我有更多时间,我会周游世界。
)这个例子通过虚拟条件句表达了一个假设情况:如果我有更多时间。
在这个情况下,使用了“had” 表示过去时间,同时跟随着模态动词“would” 和动词原形“travel”。
2. If he were here, he could give us some advice.(如果他在这里,他可以给我们一些建议。
)在这个例子中,“were” 是对于第二人称单数主语“he” 的虚拟假设。
使用了模态动词“could” 表达了一种可能性,即给我们一些建议。
3. If it didn't rain, we could go for a picnic.(如果不下雨,我们可以去野餐。
)这个例句中,“didn't” 用来表示“did not”,是对过去事实的否定陈述。
通过这个条件句表达了下雨是一个不发生的假设情况,并结合模态动词“could” 来说明在这种情况下我们可以去野餐。
4. If I had studied harder, I might have passed the exam.(如果我努力学习,或许能通过考试。
)在这个例子中,“had studied” 是对过去某个时间前的学习情况进行虚拟陈述。
使用了“might have passed”作为推测,有可能通过考试。
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。
If you fail in the exam,you will let him down.If you have finished the homework,you can go home.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。
If I were you,I would invite him to the party.I would have arrived much earlier if I had not been caught in the traffic.1.时态应用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。
(前后时态一致原则)2.总结在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.3.句式转换1)运用“祈使句+ and / or + 句子(一般将来时)”进行转换。
其中,句意表示顺承时用and,表示转折时用or(否则),If you work hard, you’ll pass the exam easily.= Work hard, and pass the exam easily.= Work hard, or you won’t pass the exam easily.2) 运用without 或with转换条件状语从句If there is no water, fish will die.= Fish will die without water.练习:用括号内所给词的正确形式填空。
初中if引导的条件状语从句用法条件状语从句用于表示一个条件或前提,它通常由if引导。
条件状语从句通常指的是未来可能发生的事情,它与主句之间存在因果关系。
条件状语从句的基本结构是“if +条件句子,主句”。
其中条件句子可以是陈述句、祈使句或者问句。
例如:-如果你学习努力(条件句子),你会取得好成绩(主句)。
-倘若明天下雨(条件句子),我们就不去度假(主句)。
-要是他来了(条件句子),请告诉他我会晚点到(主句)。
以下是一些拓展用法:1.构造虚拟条件句子:虚拟条件句子用来表达与现实相反的假想情况。
主句的情态动词常常是“would”,而条件句中的动词需使用过去时态。
例如:-如果我有足够的钱(条件句子,现在假设),我就会买一辆新车(主句)。
-如果我能回到过去(条件句子,现在不可能),我会改变很多事情(主句)。
2.使用倒装结构:如果条件句以“had”或是“were”开头时,可以使用倒装结构。
例如:- Had I known you were sick(条件句子),I would have visited you(主句).- Were I taller(条件句子),I could reach the top shelf (主句).3.使用“unless”表示否定条件:除了使用“if”之外,我们也可以使用“unless”来引导否定条件状语从句。
例如:- Unless you study hard(条件句子),you won't pass the test(主句).- We won't have a picnic(主句)unless it stops raining (条件句子).总之,条件状语从句用于表示可能发生的条件情况,其语法结构为“if +条件句子,主句”。
拓展用法包括虚拟条件句子、倒装结构和使用“unless”来表示否定条件。
if的虚拟语气的用法一、引言在英语语法中,if的虚拟语气是一种常见且重要的语法结构。
它用于表达假设、推测和愿望等非现实情况下的条件句。
掌握好if的虚拟语气的用法不仅可以使我们更加流利地表达自己的观点,还能帮助我们理解他人所说的话。
本文将详细介绍if的虚拟语气的用法,以便读者能够准确理解并运用其中。
二、假设条件当我们谈论一个假设或非事实条件时,就需要使用if从句来表达虚拟语气。
以下是一个例子:如果我有更多时间,我会去旅行。
这个句子中,“如果我有更多时间”表示一个假设条件,后面的“我会去旅行”则表示与此条件相对应的结果。
在这种情况下,if从句使用过去式动词来表示与现实不符合或非真实事件。
主句则使用would来表达结果。
需要注意的是,在utilize基本形态时,要确保主从句之间时态一致,并且使用were代替was以避免错误。
三、现在事实与过去事实除了表示假设条件外,if还可用于表示对现在和过去事实的虚拟语气。
以下是一些例子:1. If I were rich, I would buy a big house.2. If she had studied harder, she would have passed the exam.在第一个例句中,使用了if的虚拟语气来表达与现实相反的情况:我不是富有。
第二个例句则表示对过去事件的虚拟语气:她没有通过考试。
需要注意的是,过去时态与过去完成时用于if从句中。
主从句之间时态要求一致,并使用would或could等情态动词来表示结果。
四、祝愿和建议if的虚拟语气也可用于表达祝愿和建议。
以下例子将说明其用法:1. If I were you, I would apologize to her.2. If only he could speak another language, he would have more job opportunities.在这里,第一个例子中的虚拟条件“如果我是你”,强调了说话人想给对方的建议;第二个例子中,则表达了希望他能够掌握更多语言以获得更多就业机会。
if引导的条件状语从句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 .11. If I_____(have) time tonight ,I _______(finish) the book I’m reading.12. If it ______(rain) next weekend , we_______(not be able to ) plant the vegetable .13. If it_______(rain),we______(stay) at home .14.If she______(arrive) ,she _____(phone) me .15. If he_____(call),tell him I’ll ring back .if 条件状语从句的时态练习一.在正确的答案下划一条线。
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 wa there if we can't find a buIf it rain tomorrow ,we wi not go to the ooWhat wi ou do if ou find a e, he wi bring hi vioin典型例题The voeba match wi be e eterda, I houd / woud have tod him about it含义:He did not come eterda, o I did not te him about itIf he had not been i and mied man cae, he woud have made greater e earier, ou woud have met him=If ou had come earier, ou woud have met himShoud it rain, the croe to our meeting tomorrow2)在宾语从句中的应用在表示命令、建议、要求等一类动词后面的从句中。
order, ugget, mand, init houd doI ugget that we houd hod a meeting net weeHe inited that he houd be ent there注意:如ugget, init不表示"建议" 或"坚持要某人做某事时",即它们用于其本意"暗示、表明"、"坚持认为"时,宾语从句用陈述语气。
if条件句中的时态应用
if是高考考查热点之一。
同学们往往把它的时态容易判断错误。
笔者就if中的时态应用总结如下:
一.意“如果”表真实条件。
引导真实条件句。
从句要求用一般现在时表将来。
If it rains tomorrow , we `ll stay at home.
如果明天下雨的话,我们将呆在家里。
If they come tomorrow , we`ll have a meeting.
如果他们明天来的话,我们就开个会。
注意:在表示“愿意”或“不愿意”时,if 后可以跟will 或won’t.。
如:If you won’t go , I’ll go alone.
如果你愿意去,我就自己去。
二.意“假如”表虚拟条件。
引导虚拟条件句。
表示与事实相反的假设。
虚拟条件句和主句的时态构成如下:
If I were a bird ,I could fly in the air .
如果我是一只小鸟,我就会在天上飞。
If I had enough money now, I would lend it to you .
如果我现在有足够钱的话,我就会借给你。
If it should rain tomorrow, the race would be put off.
如果明天下雨的话,比赛就会推迟。
If you had arrived earlier that day , you might have met her.
如果那天你早点到的话,你就会遇见她了。
三.意“是否,是不是”引导间接问句。
当主句为现在时时,从句应用适当的时态。
当主句为过去时时,从句应当遵循时态一致的原则,要采用相应的过去时态。
I don’t know if they will come tomorrow.
我不知道他们明天是否会来。
He asked if they would come the next day.
他问他们第二天是否会来。
注意:在正式的文件中,若句中有助动词had 、were 、should,则将其提前,省略if.
Had it not been for your help,we would not have achieved so much.
要不是你的帮助,我们不会取得如此大的成绩。
四.固定搭配:
① if only :意“要是……就好了”,表示一种不真实的条件。
其后接从句。
从句用虚拟语气。
用一般过去时表示现在没有实现的愿望;对过去没有实现的愿望从句用过去完成时。
If only I had taken mother’s advice.
我要是听妈妈的建议就好了。
If only I could speak several foreign languages .
我要是能讲几种外语就好了。
区别 only if: :意“只有在……条件下才……”用来加强从句的语气。
当其位于句首时,主句用倒装语序。
He would succeed only if he tried hard .
→Only if he tried hard ,would he succeed.只有他努力他才会成功。
②:as if /though意“好象”引导状语从句或表语从句。
当从句的内容为不真实情况时要采用虚拟语气。
与现在事实相反从句用一般过去时,与过去事实相反从句用过去完成时。
与将来事实相反从句用would (could ,might )+动词原形She cried as if her heart could be broken.她哭得好象心都要碎了。
③:even if 意“即使、纵使”连词,引导让步状语从句。
Even if he is poor ,she loves him.即使他很穷,她仍然爱他。
【巩固练习】
1.She seldom ,_____,blames her failure on others.
A. if ever
B. if any
C. if necessary
D. if possible
2. I had never spent a more worrying day. It seemed _____the day would never end.
A. as if
B. even if
C. as soon as
D. as long as
3. If a man _____succeed, he must work as hard as he can .
A. will
B. is to
C. is going to
D. should
4. If it _____tomorrow, we’ll go roller-skating.
A. isn’t rain
B. won’t rain
C. doesn’t rain
D. doesn’t fine
think it is necessary for my 19-year-old son to have his own mobile phone,for I sometimes want to make sure if he ___ home for dinner .(06高考)
A e
B es C. has come D . will come
6 .In time of serious accidents ,___we know some basic things about first
aid ,we can save lives.(06高考)
A . whether B. until C .if D .unless
7 .If you ____ wait over there for a minute ,Mr. Smith ,I’ll tell our manager you’ve arrived.
A. must
B. should
C. will
D. can
for the doctor’s careful treatment ,he ____till last year.
A. If it is not ;can’t live
B. Were it not ;couldn’t live
C. Had it not been ;couldn’t have lived
D. If it wasn’t ;can’t live
9. It would be impossible for him to leave hospital tomorrow if he ___first aid when the accident happened.
A hadn’t be given
B .wasn’t be given
C. shouldn’t be given
D. wouldn’t be given
I ___plan to do anything I wanted to ,I’d like to go to Tibet and travel through as much of it as possible.(05高考)
A. would B .could C .had to D . ought to
答案:1A2A3B4C5D6C7C8C9A10B。