Unit 8Let’s communicate. Section AGrammar Focus语法专题精讲 -2025-2026学年人教版（2024）八年级英语上册

Unit 8 Let’s communicate. Grammar Focus语法专题精讲 if引导的条件状语从句 一、概念 1. if 意为“如果”：表示“假如从句动作发生，就会有主句动作发生”。 1. 从句位置：可放 主句前（用逗号隔开）或 主句后（不用逗号）。 1. unless = if...not（除非/如果不）： ▶ You won’t pass the exam unless you study hard. = You won’t pass the exam if you don’t study hard. 二、句型转换 原句（if从句） 转换句型 示例 肯定意义：If + 从句, 主句. 祈使句 + and + 句子 If you study hard, you can pass the exam. → Study hard, and you can pass the exam.（努力学习，你就能通过考试。） 否定意义：If + 否定从句, 主句. 祈使句 + or + 句子 If you don’t hurry up, you will be late. → Hurry up, or you will be late.（快点，否则你会迟到。） 三、时态呼应（主将从现：从句用 一般现在时，主句：） 1. 主句为一般将来时（will + 动词原形）：▶ If she comes, I’ll call you up. 如果她来了，我将给你打电话。 1. 主句是祈使句（动词原形开头）：▶ Please go to see the doctor if you don’t feel well. 如果你感觉不舒服，请去看医生。 1. 主句含有情态动词（can/may/must等 + 动词原形）：▶ If he goes on smoking, it may be harmful to his health. 如果他继续吸烟，这可能对他的健康有害。 语法专题精练 Ⅰ. 单项选择. 1. (2025 长春) It is really dangerous ______ people run the red traffic light.A. unless B. if C. though D. until 2. （2025安徽）Our country will be much better for everyone in future ______ we all do something to help now.A. if B. before C. so that D. even though 3. (2025 福建) You can feel better ______ you take a walk in the park just for 20 minutes.A. if B. before C. until 4. (2025 广元) —When is the school sports meeting?—It is going to be held next Thursday if it ______ that day.A. rains B. will rain C. won't rain D. doesn't rain 5. (2025 绥化) He ______ much healthier if he ______ enough exercise in his free time.A. is; take B. will be; takes C. will be; take 6. (2024 山东青岛) You won't catch the early bus ______ you get up right now.A. if B. unless C. though D. until 7. (2025 江苏南京) If it ______ tomorrow, we'll stay at home and watch movies.A. rain B. rains C. will rain D. rained 8. (2025 湖北武汉) ______ you practice speaking English every day, you'll make great progress.A. If B. Unless C. Though D. Before 9. (2025 广东广州) —What will you do ______ it is fine tomorrow?—I'll go hiking with my family.A. if B. unless C. because D. when 10. (2025 四川成都) If he ______ to the party, he will bring a big gift.A. come B. comes C. will come D. came 11. (2025 浙江杭州) You can't improve your writing skills ______ you keep practicing.A. if B. unless C. though D. until 12. (2024 陕西西安) If it ______ sunny this weekend, we ______ camping.A. is; go B. will be; go C. is; will go D. will be; will go 13. (2025 辽宁沈阳) ______ you don't give up, your dream will come true one day.A. If B. Unless C. Though D. Because 14. (2025 福建厦门) —Will you go to the concert with me?—______ I finish my homework first.A. If B. Unless C. When D. After 15. (2025 湖南长沙) If she ______ free tomorrow, she ______ to the library.A. is; goes B. will be; goes C. is; will go D. will be; will go Ⅱ. 按要求完成下列各题，每空一词. 16. Get up early, or you will be late for the meeting.（改为同义句）______ you ______ get up early, you will be late for the meeting. 17. Finish your homework and you can watch TV.（改为同义句）______ you finish your homework, you ______ watch TV. 18. I will be available this weekend. I will visit my aunt.（用if合并为一句）______ ______ ______ available this weekend, I ______ ______ my aunt. 19. I can finish the work on time. He'll help me.（用if合并为一句）______ he ______ ______, I ______ finish the work on time. 20. You won't have a better life unless you work harder.（改为同义句）You won't have a better life ______ you ______ work harder. 21. Turn off the lights when you leave the room.（用if改写）______ you leave the room, turn off the lights. 22. You can join the club if you like reading.（改为同义句，用祈使句+and）______ reading, ______ you can join the club. 23. If we don't protect the environment, we will lose our home.（改为同义句，用祈使句+or）______ the environment, ______ we will lose our home. 24. She will be happy if she gets the gift.（对划线部分提问）______ ______ she be happy? 25. I will go shopping with you if I have time tomorrow.（改为否定句）I ______ go shopping with you if I ______ have time tomorrow. 参考答案 Ⅰ. 单项选择 1.B 2. A 3. A 4. D 5. B 6. B 7. B 8. A 9. A 10. B 11. B 12. C 13. A 14. A 15. C Ⅱ. 按要求完成下列各题 16. If; don’t 17. If; can 18. If I am; will visit 19. If; helps me; can 20. if; don’t 21. If 22. Like; and 23. Protect; or 24. When will 25. won’t; don’t 学科网（北京）股份有限公司 $$