Unit 7语法讲义- 2025-2026学年沪教版八年级英语上册

该初中英语讲义通过表格系统梳理条件状语从句知识体系，按“客观事实/习惯性动作-未来事件”场景分类，对比“主现从现”与“主将从现”的从句、主句时态规则，并用口诀“条件句表可能主将从现，表事实主从现在”总结关键区别，清晰呈现语法要点内在联系。 讲义亮点在于分层练习设计，单项选择（如辨析unless与if的第1题）和语法填空（如自然规律时态填空“If water reaches 100°C, it ______ (boil)”）覆盖基础到综合应用，培养思维品质与学习能力。口诀助基础学生记忆规则，多样化练习满足不同层次需求，教师可据此实施精准复习教学。

条件状语从句（二） if条件句主现从现 当 if引导的条件状语从句表示客观事实、普遍真理或习惯性动作时，遵循以下时态规则： · 主句：一般现在时（动词用原形或第三人称单数形式）。 · 从句：一般现在时（动词用原形或第三人称单数形式）。 · 本质：用一般现在时表示将来可能发生的情况（主句结果），从句用一般现在时说明条件。​ E.g.: If you heat ice, it melts. 如果加热冰，就会融化。 If you take a fish out of water, it dies. 如果把鱼从水里捞出来，鱼就会死。 If...not/Unless引导的条件句 unless：意为“除非；如果不”，表示唯一例外条件，相当于“if...not”（但语义更强调“排除某种情况”）。语气：通常用于正式或书面语境，隐含“除此之外，其他情况均成立”的意味。 E.g.: You won’t pass the exam unless you study hard. = If you don’t study hard, you won’t pass the exam. 除非你努力学习，否则你不会通过考试。 I won’t go to the party unless you come with me. = I won’t go to the party if you don’t come with me. 如果你不和我一起去，我就不会去派对。 场景 从句时态 主句时态 示例 客观事实/普遍真理 一般现在时 一般现在时 If you heat ice, it melts. 习惯性动作/规律结果 一般现在时 一般现在时 If you water a plant, it grows. 未来具体事件 一般现在时 一般将来时 If she comes, I will call you. 关键区别： · “主现从现”强调普遍性（如自然规律、习惯）； · “主将从现”强调未来特定事件的计划或预测。 If 引导条件状语从句口诀：条件句，放在前，逗号要放句中间，条件句，表可能，主将从现很简单，条件句，表事实，主从现在记心间。 单项选择 1. You won’t have a chance to win the contest ______ you don’t prepare enough. A. unless B. though C. if D. after 2. The college students won’t go on the graduation trip ______ they raise enough money for it. A. if B. because C. unless D. when 3.  Your mother has just fallen asleep. Don’t wake her up ______ it’s really necessary. A. because B. unless C. if D. though 4. We can’t judge if the information from AI is right ______ we have a clear mind. A. after B. because C. unless D. since 5. We may face serious problems ______ we take better care of the Earth. A. if B. unless C. though D. as 6. You won’t be allowed into the concert ______ you show your ticket at the entrance. A. if B. unless C. though D. since 7. I’ll be able to finish the project on time ______ there are unexpected delays. A. when B. because C. unless D. if 8. ______ you enjoy a book, it doesn’t matter if you’re reading it for the first time or the fifth. A. Unless B. Until C. Because D. If 9. It will be difficult for Gary to complete all the tasks ______ he can manage the time well. A. if B. although C. because D. unless 10. You’ll miss the interesting details in the story ______ you pay special attention. A. unless B. as long as C. if D. because 11. ______ the rain stops, the organizers are very likely to cancel the fireworks display. A. Unless B. Until C. Because D. If 12. Give plants water. The crops won’t grow very well ______ it rains soon. A. unless B. if C. because D. although 13. Your education will be incomplete ______ you have practical life skills. A. if B. although C. because D. unless 14. According to the traffic rule, we mustn’t ride a bike ______ we wear a helmet (头盔) . A. if B. when C. unless D. because 15. The nurse won’t leave her patients ______ she’s sure they’re all taken good care of. A. if B. because C. when D. unless 16. Sorry sir, your order ______ if you fail to pay for it in 15 minutes. A. canceled B. is canceled C. was canceled D. will be canceled 17. She will finish the project in time ______ the workshop is not available. A. unless B. if C. or D. after 18. If you ______ a list of things that you have to do, you won’t forget to do them. A. make B. will make C. made D. are making 19. Students are not supposed to enter the teachers’ office ______. A. unless they are allowed to B. if they want to ask questions C. when they are asked to come in D. if they will ask questions 20. If it ______ tomorrow, we will go to the park. A. isn’t rain B. don’t rain C. doesn’t rain D. won’t rain 答案：1-5 CCBCB 6-10 BCDDA 11-15 AADCD 16-20 DAAAC 单句语法填空 1. If water reaches 100°C, it _______boils______ (boil). 2. Put up your hands _____if________ you have any questions to ask. 3. If the sun shines on a mirror, the light ______reflects______ (reflect) back. 4. If it doesn’t rain, we ______will have______ (have) a picnic tomorrow. 5. If a planet orbits the Sun, it _____follows______ (follow) an elliptical (椭圆的) path. 6. ____Unless________ I feel tired, I usually go for a run in the evening. 7. _____If______ you read every day, you will improve your vocabulary. 8. If you touch my phone again, I _____will be_______ (be) angry. 9. If a shape has four equal sides and angles, it ______is______ (be) a square. 10. If you drop an object, it ____falls________ (fall) to the ground. 11. You _____won’t recover________ (not recover) unless you take the medicine on time. 12. If you mix vinegar and baking soda, they _____produce_______ (produce) bubbles. 13. If they win the game, they ________will celebrate_________ (celebrate) tonight. 14. ___Unless_________ you take the medicine, your cough won’t get better. 15. ____If________ we don’t leave now, we will miss the train. 16. I never go to bed late ____unless_______ I have an exam the next day. 17. ____Unless________ you review your notes, you’ll forget what you learned. 18. If you eat too much junk food, you _____will gain_______ (gain) weight. 19. ______If______ we learn a new language, we will understand different cultures better. 20. If he doesn’t meet the deadline, he _______will lose_____ (lose) his job. 1 学科网（北京）股份有限公司 $ 条件状语从句（二） if条件句主现从现 当 if引导的条件状语从句表示客观事实、普遍真理或习惯性动作时，遵循以下时态规则： · 主句：一般现在时（动词用原形或第三人称单数形式）。 · 从句：一般现在时（动词用原形或第三人称单数形式）。 · 本质：用一般现在时表示将来可能发生的情况（主句结果），从句用一般现在时说明条件。​ E.g.: If you heat ice, it melts. 如果加热冰，就会融化。 If you take a fish out of water, it dies. 如果把鱼从水里捞出来，鱼就会死。 If...not/Unless引导的条件句 unless：意为“除非；如果不”，表示唯一例外条件，相当于“if...not”（但语义更强调“排除某种情况”）。语气：通常用于正式或书面语境，隐含“除此之外，其他情况均成立”的意味。 E.g.: You won’t pass the exam unless you study hard. = If you don’t study hard, you won’t pass the exam. 除非你努力学习，否则你不会通过考试。 I won’t go to the party unless you come with me. = I won’t go to the party if you don’t come with me. 如果你不和我一起去，我就不会去派对。 场景 从句时态 主句时态 示例 客观事实/普遍真理 一般现在时 一般现在时 If you heat ice, it melts. 习惯性动作/规律结果 一般现在时 一般现在时 If you water a plant, it grows. 未来具体事件 一般现在时 一般将来时 If she comes, I will call you. 关键区别： · “主现从现”强调普遍性（如自然规律、习惯）； · “主将从现”强调未来特定事件的计划或预测。 If 引导条件状语从句口诀：条件句，放在前，逗号要放句中间，条件句，表可能，主将从现很简单，条件句，表事实，主从现在记心间。 单项选择 1. You won’t have a chance to win the contest ______ you don’t prepare enough. A. unless B. though C. if D. after 2. The college students won’t go on the graduation trip ______ they raise enough money for it. A. if B. because C. unless D. when 3.  Your mother has just fallen asleep. Don’t wake her up ______ it’s really necessary. A. because B. unless C. if D. though 4. We can’t judge if the information from AI is right ______ we have a clear mind. A. after B. because C. unless D. since 5. We may face serious problems ______ we take better care of the Earth. A. if B. unless C. though D. as 6. You won’t be allowed into the concert ______ you show your ticket at the entrance. A. if B. unless C. though D. since 7. I’ll be able to finish the project on time ______ there are unexpected delays. A. when B. because C. unless D. if 8. ______ you enjoy a book, it doesn’t matter if you’re reading it for the first time or the fifth. A. Unless B. Until C. Because D. If 9. It will be difficult for Gary to complete all the tasks ______ he can manage the time well. A. if B. although C. because D. unless 10. You’ll miss the interesting details in the story ______ you pay special attention. A. unless B. as long as C. if D. because 11. ______ the rain stops, the organizers are very likely to cancel the fireworks display. A. Unless B. Until C. Because D. If 12. Give plants water. The crops won’t grow very well ______ it rains soon. A. unless B. if C. because D. although 13. Your education will be incomplete ______ you have practical life skills. A. if B. although C. because D. unless 14. According to the traffic rule, we mustn’t ride a bike ______ we wear a helmet (头盔) . A. if B. when C. unless D. because 15. The nurse won’t leave her patients ______ she’s sure they’re all taken good care of. A. if B. because C. when D. unless 16. Sorry sir, your order ______ if you fail to pay for it in 15 minutes. A. canceled B. is canceled C. was canceled D. will be canceled 17. She will finish the project in time ______ the workshop is not available. A. unless B. if C. or D. after 18. If you ______ a list of things that you have to do, you won’t forget to do them. A. make B. will make C. made D. are making 19. Students are not supposed to enter the teachers’ office ______. A. unless they are allowed to B. if they want to ask questions C. when they are asked to come in D. if they will ask questions 20. If it ______ tomorrow, we will go to the park. A. isn’t rain B. don’t rain C. doesn’t rain D. won’t rain 单句语法填空 1. If water reaches 100°C, it _____________ (boil). 2. Put up your hands _____________ you have any questions to ask. 3. If the sun shines on a mirror, the light _____________ (reflect) back. 4. If it doesn’t rain, we _____________ (have) a picnic tomorrow. 5. If a planet orbits the Sun, it _____________ (follow) an elliptical (椭圆的) path. 6. _____________ I feel tired, I usually go for a run in the evening. 7. _____________ you read every day, you will improve your vocabulary. 8. If you touch my phone again, I _____________ (be) angry. 9. If a shape has four equal sides and angles, it _____________ (be) a square. 10. If you drop an object, it _____________ (fall) to the ground. 11. You _______________ (not recover) unless you take the medicine on time. 12. If you mix vinegar and baking soda, they _____________ (produce) bubbles. 13. If they win the game, they __________________ (celebrate) tonight. 14. _____________ you take the medicine, your cough won’t get better. 15. _____________ we don’t leave now, we will miss the train. 16. I never go to bed late ____________ I have an exam the next day. 17. _____________ you review your notes, you’ll forget what you learned. 18. If you eat too much junk food, you _____________ (gain) weight. 19. _____________ we learn a new language, we will understand different cultures better. 20. If he doesn’t meet the deadline, he _____________ (lose) his job. 1 学科网（北京）股份有限公司 $