Unit 2 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(Ⅱ) 语法串烧 我的发现 　　The new term starts.On campus, there comes a foreign exchange student.From his wearing, we can see he must be from a wealthy family.He also looks very gentle, so he can't be difficult to get along with.Now, he is talking with a student.According to his English accent, I know he may be from US.Last term, there were two exchange students from America in my class.However, I didn't see their names on the class list.I guess that they must have gone back to their country.If this exchange student could be in my class, I will have more chances to practice my spoken English with him. ①情态动词can, may, must, might, could等后接动词原形可以表示对现在或将来情况的推测； ②这些情态动词后接现在完成时态则可以表示对过去情况的推测。 学生用书第51页 1．can与could的用法 (1)表示能力(could是过去式)。 My grandmother can do some shopping on the Internet，but she couldn't last year. 我奶奶会网购了，但是去年她还不会。 (2)表示猜测，意为“可能”，一般用于疑问句和否定句(could是过去式)。 Can this news be true? 这则消息是真的吗？ (3)表示请求和许可(could表示更委婉的语气，回答时只能用can)。 —Can/Could I go now? —Yes，you can. ——我现在可以走了吗？ ——是的，可以。 (4)用于肯定的陈述句中，表示理论上或习惯上的可能性。 As we all know，anyone can make mistakes. 我们都知道，任何人都可能犯错。 (5)习惯用法“cannot...too...”表示“无论怎样……都不过分，越……越好”。有时cannot可用can never替代。 We cannot thank you too much for what you've done for us.对于你们为我们所做的一切，我们怎么感激你们都不为过。 ◎巧学活用1——单句语法填空 ①I could speak Arabic fluently when I was a child and lived in Morocco.But now, I can just say a few things in the language. ②—I heard they went skiing in the mountains last winter. —It couldn't be (not be) true because there was little snow there. ③—Do you know where David is? I couldn't find him anywhere. —Well, he can't have gone (go) far — his coat is still here. ④Mr Smith is on time for everything.How can/ could it be that he was late for the important meeting? 2．may与might的用法 (1)表示允许、许可。might在语气上比may更委婉。以may/might开头的问句在否定回答中要用mustn't/can't。 —May/Might I play the computer games after supper? —Yes，you may./No，you mustn't/can't. ——晚饭后我可以玩电脑游戏吗？ ——是的，可以。/不，不行。 (2)表示把握不大的推测，意为“可能”，用于肯定句。 might语气更加不肯定，指现在或将来，只有在宾语从句中might do /be才表示过去的可能性。 ①I think he may come tomorrow. 我认为明天他可能会来。 ②He told me he might be late. 他告诉我他可能会迟到。 (3)may用于祈使句表示祝愿。 May you succeed.祝你成功。 (4)may/might as well最好还是……，不妨…… You might as well do it now.你最好还是现在做吧。 ◎巧学活用2——单句语法填空 ①He had been working for more than 11 hours.He must be tired after such hard work.He may prefer to get some rest. ②Sorry, I'm late.I may/ might have turned (turn) off the alarm clock and gone back to sleep again. ③—Excuse me.Is this the right way to the Children's Palace? —Sorry, I am not sure.But it might be. 3．must的用法 (1)表示“必须”，语气比should，ought to强烈。其否定形式为mustn't (不准；禁止)。 学生用书第52页 You mustn't do that，because you must keep your word.你不能那么做，因为你得遵守诺言。 [名师点津] 以must开头的一般疑问句的肯定回答中要用must，否定回答中要用needn't/don't have to。 —Must I finish the paper today? —Yes，you must./No，you needn't/don't have to. ——今天我必须完成论文吗？ ——是的，你必须。/不，你不必。 (2)表示有把握的肯定推测，只能用在肯定句中，意为“一定；准是”；在否定句、疑问句中要用can't代替。 You have worked hard all day.You must be tired. 辛苦工作了一整天，你一定累了。(对现在情况的推测判断) (3)表示感情色彩，意为“偏偏；偏要”，常指令人不快的事情。 The car must break down just when I was about to start. 我正要出发时车偏偏抛锚了。 ◎巧学活用3——单句语法填空 ①If you want to learn to speak English fluently, you must work hard. ②—It must be John who is in the office. —No, it can't be him.I saw him off at the airport half an hour ago. ③His watch must have stopped(stop).I will go and call him. 4．情态动词＋have done must have done 过去一定已经做了(表推测) may/might have done 过去也许做了(表推测) needn't have done 本不必做而做了 can't/couldn't have done 过去不可能做过(表推测) should have done 本该做而未做 From what you said，she must have told you all about it. 从你所说的来看，她一定把一切都告诉你了。 You should have told me earlier or I might have gone with them. 你本应该早点告诉我，不然的话我或许就会和他们一块去了。 You needn't have told them about it. 你本来没有必要告诉他们那件事。 They can't have gone out because the light is on. 他们不可能出去了，因为灯亮着。 ◎巧学活用4——完成句子 ①他不可能错过火车；他提前两个小时就到达火车站了。 He can't have missed the train；he arrived at the train station two hours early. ②保罗在演讲比赛中表现出色。上周他一定练习了很多次。 Paul did a great job in the speech contest.He must have practised many times last week. ③如果你多给她一些机会，她可能会取得更大的进步。 She might have achieved greater progress, if you had given her more chances. ④在你告诉他之前他就知道这件事了，因此你没必要告诉他。 He had known the matter before you told him, so you needn't have told it to him. 学科网（北京）股份有限公司 $