Unit2语法(情态动词)讲解与练习-2026-2027学年北师大版英语八年级上册

本初中英语讲义聚焦情态动词must/mustn’t、have to/don’t have to、should/shouldn’t的详细讲解，通过“含义-语气-核心区分”分点梳理，结合总结表格整合，易混对比例句巩固，构建从具体辨析到系统应用的学习支架。 该资料以Safety主题为情境，例句贴近生活（如“must follow safety rules”“mustn’t play with fire”），助力语言能力提升。通过对比辨析（如must与have to的主客观差异）培养思维品质，配套分层练习（填空、单选等）帮助课后查漏补缺，提升学习能力，课中辅助教师高效授课，课后强化知识掌握。

Unit2 Safety语法讲解与练习 语法:情态动词详细讲解与练习 一、核心情态动词辨析 1. must / mustn’t ✅ must：必须（主观义务，说话人认为有必要；规章制度硬性要求），无人称、时态变化，后接动词原形 例句 1：You must follow the safety rules. 你必须遵守安全规则。（硬性规定） 例句 2：We must call 120 when someone is badly hurt. 有人重伤时我们必须拨打 120。 ✅ mustn’t：禁止，不准（强烈禁止，绝对不能做，违规） 例句 1：You mustn’t run in the hallway. 不准在走廊奔跑。 例句 2：We mustn’t play with fire. 我们严禁玩火。 ⚠️易错：mustn’t ≠ “不必”；mustn’t 是禁止；“不必” 要用 don’t have to /needn’t 2. have to / don’t(doesn’t/didn’t) have to ✅ have to：不得不（客观要求，外部环境、规则迫使，并非自己主观想做；有人称时态变化） 一般现在：have to /has to；一般过去：had to 例句 1：He hurt his leg, so he has to stay in bed. 他腿受伤了，不得不卧床休息。 例句 2：We had to leave the building because of the fire. 因为火灾，我们不得不离开大楼。 ✅ don’t/doesn’t/didn’t have to = needn’t：不必，没有必要做（可做可不做） 例句 1：You don’t have to carry heavy things. I will help you. 你不必搬重物，我来帮你。 例句 2：You needn’t take all the first-aid supplies. 你不必带上全部急救物资。 must vs have to must：主观必须（我觉得必须；法律 / 规定）无变形 have to：客观不得不（外界迫使）有人称时态变化 3. should / shouldn’t ✅ should：应该（建议、劝告，较弱的义务，语气比 must 轻；无人称时态变化，后+动词原形） 例句 1：You should learn basic first aid. 你应该学习基础急救知识。（建议） 例句 2：We should keep calm when we meet danger. 遇到危险我们应该保持冷静。 ✅ shouldn’t：不应该（劝告，不建议做，较弱的禁止，语气弱于 mustn’t） 例句 1：You shouldn’t touch the hot water. 你不应该去碰热水。 例句 2：We shouldn’t push others when escaping from fire. 火灾逃生时我们不应该推搡别人。 二、总结表格 情态短语 含义 语气 核心区分 must 必须 强（主观 / 规定） 说话人认为一定要做 mustn’t 禁止，不准 极强 绝对不能做，违反规定 have to 不得不 强（客观） 外界情况迫使，非自愿，有时态变化 don’t have to / needn’t 不必 弱 可做可不做，没有强制要求 should 应该 中等 提建议、劝告 shouldn’t 不应该 中等 劝阻，不建议做 三、必考要点 以上情态动词后面全部 + 动词原形，不能加 to do /doing must，should：没有三单，没有时态变化；have to 会随人称时态变：has to, had to 否定区分大坑： ✅ mustn’t = 禁止 ✅ don’t have to /needn’t = 不必 回答 Must 引导的一般疑问句： —Must I leave now? —Yes, you must. —No, you don’t have to / needn’t.（❌No, you mustn’t） 四、易混对比例句（Safety 主题） You must stop when the fire alarm rings.（规定，必须停下） You have to wear a mask in this room.（房间规定，客观要求） You mustn’t open the door when there is smoke.（严禁开门） You don’t have to take the blanket.（没必要带毯子，可以不带） You should check the fire exit regularly.（建议，应该定期检查安全出口） You shouldn’t jump from high places.（不建议，不要从高处跳下） 配套专项练习 大题一：用 must /mustn’t /have to /don’t have to /should/shouldn’t 填空 1.You ________ touch the broken glass. It will cut your fingers.（禁止） 2.We ________ keep quiet in the safety lesson.（必须） 3.He hurt his hand, so he ________ see a doctor.（不得不） 4.You ________ take your umbrella. It won’t rain.（不必） 5.We ________ learn how to call 120.（建议，应该） 6.You ________ run when there is a fire.（不应该） 7.—________ I finish the safety report today? —Yes, you ________. 8.—________ I stay here? —No, you ________. You can go home.（不必） 9.Students ________ follow school safety rules.（必须） 10.You ________ play with matches. It’s dangerous.（禁止） 11.She ________ leave early yesterday because of the accident.（had to，不得不） 12.You ________ worry about him. He is safe now.（不必） 13.Everyone ________ stay calm in danger.（建议，应该） 14.We ________ waste water in the lab.（不应该） 15.You ________ park your bike at the gate.（禁止） 16.If you get burned, you ________ put the wound under cold water.（必须） 17.You ________ bring your first-aid book. We have copies.（不必） 18.He ________ go to hospital last night. His leg was hurt badly.（不得不） 19.We ________ check the fire alarm every month.（建议） 20.You ________ talk loudly in the hospital.（不应该） 21.You ________ enter this room. It’s dangerous inside.（禁止） 22.We ________ help each other when escaping fire.（应该） 23.You ________ take medicine without asking doctors.（禁止） 24.They ________ leave at once when the alarm goes off.（必须） 25.You ________ buy new bandages. We still have some.（不必） 大题二：单项选择 1.You ______ play near the fire. It is very dangerous. A. must B. mustn’t C. should D. shouldn’t 2.We ______ learn first aid. It’s good for us. A. mustn’t B. should C. don’t have to D. have to 3.My arm hurts. I ______ go to the hospital. A. have to B. must C. should D. shouldn’t 4.—Must I clean the safety corner now? —No, you ______. You can do it tomorrow. A. mustn’t B. shouldn’t C. don’t have to D. can’t 5.You ______ touch the hot pot. You may get burned. A. must B. should C. shouldn’t D. have to 6.We ______ wear helmets when riding bikes. It’s the rule. A. must B. shouldn’t C. don’t have to D. needn’t 7.You ______ take your coat. The room is warm enough. A. must B. have to C. don’t have to D. mustn’t 8.You ______ shout in the hospital. A. must B. mustn’t C. have to D. should 9.Everyone ______ keep calm when facing danger. A. should B. shouldn’t C. mustn’t D. don’t have to 10.He ______ stop his car, because the traffic light was red. A. have to B. had to C. has to D. must 11.You ______ worry. Nothing serious happened. A. must B. should C. don’t have to D. have to 12.We ______ push others in the fire exit. It’s dangerous. A. shouldn’t B. should C. must D. have to 13.—______ I obey the school safety rules? —Yes, you ______. A. Must; must B. Must; don’t have to C. Should; shouldn’t D. Mustn’t; must 14.You ______ smoke here. Look at the sign “No Smoking”. A. should B. shouldn’t C. mustn’t D. don’t have to 15.You ______ learn safety knowledge. It can save your life. A. shouldn’t B. needn’t C. should D. don’t have to 大题三：句子改写 1.It is necessary for you to learn safety rules.（用 must 改写） ____________________________________________________________ 2.You are not allowed to run in the lab.（用 mustn’t 改写） ____________________________________________________________ 3.I have to stay at home because of the heavy rain.（改为否定句） ____________________________________________________________ 4.You should put the medicine out of children’s reach.（用 must 改写） ____________________________________________________________ 5.Must I finish the safety exercise now?（否定回答） ____________________________________________________________ 6.It’s a good idea to check the fire exit every week.（用 should 改写） ____________________________________________________________ 7.He has to call 120 at once.（改为一般疑问句） ____________________________________________________________ 8.You don’t need to bring water.（同义替换，don’t have to） ____________________________________________________________ 9.You must keep quiet in the hospital.（改为否定句，禁止含义） ____________________________________________________________ 10.We should help people who are hurt.（改为一般疑问句） ____________________________________________________________ 大题四：汉译英 1.你必须遵守校园安全规则。 ____________________________________________________________ 2.禁止在楼道里奔跑。 ____________________________________________________________ 3.他的膝盖受伤了，所以不得不去医院。 ____________________________________________________________ 4.你不必带上急救箱，我这里有一个。 ____________________________________________________________ 5.遇到危险你应该保持冷静。 ____________________________________________________________ 6.你不应该碰这个破损的电线。 ____________________________________________________________ 7.— 我必须马上离开吗？— 不，不必。 ____________________________________________________________ 8.火灾逃生时我们不应该推搡别人。 ____________________________________________________________ 9.所有人都必须学会如何拨打 120。 ____________________________________________________________ 10.你不必担心，他的伤势不重。 ____________________________________________________________ Keys 一、填空 1.mustn’t 2. must 3. has to 4. don’t have to 5. should 6.shouldn’t 7. Must; must 8. Must; don’t have to/needn’t 9. must 10. mustn’t 11.had to 12. don’t have to 13. should 14. shouldn’t 15. mustn’t 16.must 17. don’t have to 18. had to 19. should 20. shouldn’t 21.mustn’t 22. should 23. mustn’t 24. must 25. don’t have to 二、单选 1.B 2.B 3.A 4.C 5.C 6.A 7.C 8.B 9.A 10.B 11.C 12.A 13.A 14.C 15.C 三、句子改写 1.You must learn safety rules. 2.You mustn’t run in the lab. 3.I don’t have to stay at home because of the heavy rain. 4.You must put the medicine out of children’s reach. 5.No, you don’t have to / needn’t. 6.You should check the fire exit every week. 7.Does he have to call 120 at once? 8.You don’t have to bring water. 9.You mustn’t make noise in the hospital. 10.Should we help people who are hurt? 四、汉译英 1.You must follow the school safety rules. 2.You mustn’t run in the hallway. 3.His knee was hurt, so he had to go to the hospital. 4.You don’t have to bring the first-aid kit. I have one. 5.You should keep calm when you meet danger. 6.You shouldn’t touch the broken wire. 7.—Must I leave right now? —No, you don’t have to / needn’t. 8.We shouldn’t push others when escaping from the fire. 9.Everyone must learn how to call 120. 10.You don’t have to worry. His injury is not serious. 2 / 2 学科网（北京）股份有限公司 $