Unit 1 Section Ⅳ Grammar-【金版新学案】2025-2026学年高中英语必修第二册同步课堂高效讲义教师用书（外研版）

Section Ⅳ　Grammar 情态动词(Ⅰ) 语法串烧 我的发现 　　As a senior one student, Li Qing is able to adjust himself to the new school life.In classes, he has to focus himself on his teachers, or he can't grasp what his teachers have taught.Meanwhile, his teachers often tell him that he had better balance his study and play.He needn't stay up to do his homework.However, I dare say he is going to challenge himself to more subjects in one term. ①黑体词汇都是情态动词，它们后面都接动词原形。 ②情态动词一般无人称和数的变化。can和dare有时态变化，be able to和have to有人称和时态的变化。 ③构成否定句时，not放在情态动词后面。 1．can与be able to (1)can只有现在时和过去时(could)，而be able to则有更多的时态变化，在将来时、完成时和非谓语动词中只能用be able to。 This time I failed in the exam，but I'll be able to pass the exam next time. 这次我考试不及格，但下次考试我能及格。(将来时) (2)can一般指自身具有的能力，而be able to则表示经过一段时间的努力后所具有的能力，相当于manage to do或succeed in doing。 I can/am able to speak both English and French. 我会说英语和法语。 [名师点津] 现在时can与be able to没有区别，但是在过去时中二者意义不同。 All the people could escape from the burning hotel last night. 昨晚所有的人都有能力从燃烧的旅馆里逃脱出来。(有这种能力，但不一定做到) All the people were able to escape from the burning hotel last night. 昨晚所有的人都从燃烧的旅馆里逃脱出来了。(成功做到了) (3)在否定结构中was/were able to与could没有区别。 She ran fast but she couldn't/wasn't able to catch the bus. 她跑得很快可还是没能赶上公交车。 (4)can/could表示请求别人做某事，意为“能，可以”。 —Can/Could I come to see you tomorrow? —Yes，you can. ——我明天能来看你吗？ ——可以。 (5)can/could表示惊讶，常用在否定句和疑问句中。 How could you do such a silly thing？(表示惊讶) 你怎么能做那样的蠢事呢？ ◎巧学活用1——选词填空(can/could/be able to) ①If you have a good sleep，you will be able to work out this problem. 学生用书第23页 ②When I was young，I could climb any tree in the woods. 2．need的用法 (1)need作情态动词时，后跟动词原形，表示“需要，有必要”，无人称和数的变化，多用于疑问句、否定句或条件句中。其否定形式是在其后直接加not，疑问形式是直接将need提到主语前。由need构成的一般疑问句，其肯定回答用must或have to。否定回答常用needn't。 —Need I finish the work today? —Yes，you must/have to./No，you needn't. ——我需要今天干完这项工作吗？ ——是的，你必须干完。/不用，你不必干完。 There's plenty of time.You needn't drive so fast. 时间很充足，你不必开这么快。 (2)作实义动词 need作实义动词时，后可接名词、动词-ing 形式、动词不定式等，有人称、时态和数的变化，其否定形式、疑问形式都要通过助动词do构成。物作主语时need后跟doing或to be done。 There are always people who need help from others. 总会有人需要他人的帮助。 He didn't need to set off so early. 他不必那么早出发。 Do I need to leave my telephone number and address? 我有必要把电话号码和地址留下吗？ The bike needs repairing. ＝The bike needs to be repaired. 这辆自行车需要修理。 ◎巧学活用2——用所给单词的适当形式填空 ①I love the weekend，because I needn't get(get) up early on Saturdays and Sundays. ②I need to collect(collect) the parcel before leaving for England. 3．must与have to (1)must表示“必须”，语气强烈。have to表示“不得不”，意义与must相近，但又有所区别。must表示说话人的主观看法，have to则强调客观需要；must只有一种形式，而have to有人称、时态等方面的变化。 —Shall I inform him of the change of the schedule right now? —I am afraid you must，in case he comes late for the meeting. ——日程改了，我该马上通知他吗？ ——我想你必须(通知他)，以免他开会迟到。 I have to go now，because my mother is in hospital. 我现在不得不走了，因为我母亲住院了。 (2)must表示推测，意为“一定”，用于肯定句。must have done是对过去事情的推测。 Someone must have used my umbrella yesterday.I found it wet. 昨天一定有人用了我的雨伞，我发现它湿了。 (3)must含有感情色彩，意为“偏要，非要……不可”。 If you must go，at least wait until the storm is over. 如果你非要走，至少要等到暴风雨停止。 (4)mustn't 表示禁止，意为“不得，不允许；一定不要”。 That car is my property；you mustn't use it without my permission. 那辆车是我的财产，没有我的允许你不能使用它。 (5)have to表示“不得不”，有时态、人称和数的变化，其否定形式为don't/doesn't/didn't have to。 学生用书第24页 It's too late.I have to go home now. 天色太晚了，我现在得回家了。 You don't have to finish the work now. 你现在没有必要完成这项工作。 ◎巧学活用3——补全句子 ①我必须在10点之前到会。如果我想准时的话，我可能得乘出租车。 I must be at the meeting by 10：00.I will probably have to take a taxi if I want to be on time. ②新颁布的法律禁止人们酒后驾车。 The new law states that people mustn't drive after drinking alcohol. ③你不必为她辩解了。 You don't have to make excuses for her. ④一定是大卫干的。他是唯一会送你花的人。 It must have been David.He's the only one who would send you flowers. 4．dare的用法 (1)dare既可以作实义动词，也可以作情态动词。作情态动词时多用于疑问句、否定句、条件状语从句以及表示怀疑的名词性从句中，表示“敢……”。 I dare not walk through the wood at night. 夜间我不敢在小树林里走。 Dare she go home alone at night? 她敢夜间独自一个人回家吗？ How dare you say that I'm a thief? 你怎么敢说我是一个小偷呢？ [名师点津] dare作情态动词时没有第三人称单数形式，但有过去式。 He dared not tell his parents the truth yesterday. 昨天他不敢告诉父母实情。 (2)dare作实义动词时，在否定句、疑问句中动词不定式符号to也可以省略。 The children don't dare (to) make a sound while their parents are sleeping. 孩子们在父母睡觉时不敢弄出一点声音。 Does he dare (to) tell you what he has done? 他敢告诉你们他所做的事情吗？ ◎巧学活用4——用所给单词的适当形式填空 ①Dare you tell (tell) her the news? ②She dared not breathe(breathe) a word of it to anybody. ③He dares to say (say) whatever he wants to say. 5．had better的用法 had better后跟动词原形，表示“最好……”，其否定式在had better后加not。而构成疑问式时，则通常将had(而不是had better)置于主语之前。 You'd better get there before it gets dark. 你最好天黑前到达那里。 We'd better not talk so loudly. 我们最好不要这么大声说话。 What had we better do? 我们最好怎么办？ ◎巧学活用5——补全句子 ①你最好睡一会儿。 You'd better get some sleep. ②我们最好不要把别人的想法看得太重要。 We had better not attach too much importance to what other people think. 学科网（北京）股份有限公司 $