Unit 8 If 引导的条件状语从句语法知识及练习2025-2026学年人教版（2024）八年级英语上册

Unit 8 Let’s communicate If 引导的条件状语从句语法知识及练习 一、基本概念 If 引导的条件状语从句表示"如果……就……"，从句提出条件，主句说明可能的结果。 二、结构： If 引导的条件状语从句+主句 （主从句可互换位置，但 if 从句在前时需加逗号）。 If you study hard, you will pass the exam. You can borrow my book if you return it on time. 三、常见考点 1. "主将从现"原则：if 从句用一般现在时表将来，主句用将来时。 If he comes, I will be happy. 2. 主句是祈使句或情态动词： If you feel tired, drink some water. （祈使句） If you finish early, you can leave. （情态动词） 3. "Unless" = "If...not"： Unless you hurry up, you'll be late. = If you don't hurry up, you'll be late. 4、 句型转换 1. 使用“祈使句+and/or+陈述句（一般将来时）”句型转换 If you study hard, you will achieve your dream. =Study hard, and you will achieve your dream. 2. 使用without或with来转换 If there is no sunlight, plants will die. = Plants will die without sunlight. 五、易错点辨析 1. If vs. When If表示“不确定的条件”（可能发生，也可能不发生）。 If it rains tomorrow, we'll stay home.（可能下雨，可能不下） When表示“必然发生的条件”（时间状语从句）。 When summer comes, we'll go swimming.（夏天一定会来） 2. 主句不用将来时的情况 如果主句是客观事实或真理，用 “一般现在时”： If you heat ice, it melts.（自然规律） 练习巩固 一、填空题（用所给动词的正确形式填空） 1. If you ______ (not leave) now, you ______ (miss) the train. 2. Unless he ______ (apologize), I ______ (not forgive) him. 3. If it ______ (snow) tomorrow, the schools ______ (close). 4. You ______ (get) sick if you ______ (not wear) warm clothes. 5. If she ______ (have) enough money, she ______ (buy) a new phone. 6. ______ (call) me if you ______ (need) any help. 7. The teacher ______ (be) angry if you ______ (not finish) your homework. 8. If they ______ (invite) us, we ______ (go) to their party. 二、完成句子（根据中文提示完成句子） 1. If you don’t hurry up, ________________（你会迟到）. 2. ________________（如果明天不下雨）, we will go hiking. 3. You will fail the exam ________________（除非你努力学习）. 4. If you eat too much junk food, ________________（你会变胖）. 5. ________________（如果你看到Tom）, tell him to call me back. 三、单选题（10题） 1. If he ______ late again, the teacher ______ him stand outside. A. comes; will make B. will come; makes C. came; made D. comes; makes 2. You won’t catch the bus ______ you run faster. A. if B. unless C. because D. when 3. —Will you go to the concert if you ______ free? —Yes, but I’m not sure. A. are B. will be C. were D. have been 4. If you ______ your room, I ______ you watch TV. A. clean; let B. will clean; let C. clean; will let D. will clean; will let 5. ______ you don’t water the plants, they ______. A. If; die B. Unless; will die C. If; will die D. When; die 6. What ______ if I press this button? A. happens B. will happen C. is happening D. happened 7. If she ______ harder, she ______ the competition. A. tries; wins B. will try; wins C. tries; will win D. will try; will win 8. —Mom, can I play games now? —______ you finish your homework first. A. If B. Unless C. Because D. When 9. Unless you ______ quiet, the baby ______ up. A. keep; will wake B. will keep; wakes C. keep; wakes D. will keep; will wake 10. If it ______ sunny this weekend, we ______ camping. A. is; go B. is; will go C. will be; go D. will be; will go 四、选词填空 Good Communication Starts with "If" if, unless, talk, listen, understand, angry, happy, will, won’t, apologize Good communication is the key to healthy relationships. (1) ______ you want others to (2) ______ you, first learn to (3) ______ carefully to them. For example, (4) ______ your friend is (5) ______, don’t interrupt. Instead, say, “(6) ______ you tell me why you’re upset, I (7) ______ try to help.” Sometimes, small actions make a big difference. (8) ______ you remember to say “thank you,” people (9) ______ feel appreciated. But (10) ______ you never show gratitude, they (11) ______ want to help you again. Arguments happen, but (12) ______ you (13) ______ after a fight, the relationship (14) ______ improve. Remember: (15) ______ there is no communication, there is no understanding. 参考答案 一、填空题 1. don’t leave; will miss 2. apologizes; won’t forgive 3. snows; will close 4. will get; don’t wear 5. has; will buy 6. Call; need 7. will be; don’t finish 8. invite; will go 二、完成句子 1. you will be late 2. If it doesn’t rain tomorrow 3. unless you study hard 4. you will get fat 5. If you see Tom 三、单选题 1-5: A B A C C 6-10: B C A A B 4、 选词填空 1.If 2. understand 3. listen 4. if 5. angry 6.If 7. will 8. If 9. will 10. unless 11.won’t 12. if 13. apologize 14. will 15. Unless 学科网（北京）股份有限公司 $$