《中考英语总复习》考点35 条件状语从句-备战2020年中考英语考点一遍过.doc

考点35 条件状语从句条件状语从句，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作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＂主将从现＂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引导条件状语从句的连词或词组有：if(如果)，unless(除非)，as long as(只要)等如果主句是将来时，条件状语从句也用一般现在时来表示如：I will stay at home if it rains tomorrow. 如果明天下雨，我就待在家You can’t learn English well unless you work hard.除非你努力学习，否则是学不好英语的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？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 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 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. as /so long as引导的条件状语从句 as /so long as的意思是＂只要＂ So long as you’re happy, I will be happy. 只要你高兴，我就高兴。

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 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5. 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 6. 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. 如果雾再大一些，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知识拓展】 1. 在以when，before，as soon as等引导的时间状语从句，也适用＂主将从现＂原则，即如果主句是一般将来时，从句则用一般现在时 I’ll tell her the good news when she comes back. 当她回来的时候，我将把这个好消息告诉她 she will give you a call as soon as she returns.她一回来就会给你 2.If条件句的同义句：祈使句，and /or+将来时态的陈述句 Work hard, and you will make great progress.= If you work hard, you will make great progress. 如果你努力学习，你就会取得大的进步 Hurry up, or you will be late.=If you don’t hurry up, you will be late. 如果你不快点，你就要迟到了。

巧学妙记】＂ if ＂ 引导的条件状语从句的记忆口诀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真实，主将从现要遵从；条件句非真实，虚拟语气用到位一、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 dog. 6. Lana _______________(buy) a new dress if the old one _______________(be) out of style. 7. The twins _______________(fight) if they _______________(argue). 8. I _______________(sell) my paintings 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.二、完成句子 1. 如果他到的晚了会发生什么事情？ What _______________ _______________if。