Unit 9 Can you come to my party? 情态动词can&have to的用法 Can she… Can she come to the party? Yes,she can. Can he go to the baseball game? No,he can’t. He has to study. Can he… Can they come to the party? No ,they can’t. They have to study for the math test. Can they… Grammar Focus Sure, I’d love to. Can you come to my party on Saturday? Sorry, I must study for a math test. Can you go to the Sure. That sounds great. I’m afraid not. I have the flu. movies tomorrow night? Can he go to the party? No, he can’t. He has to help his parents. No. she’s not available. She Can she go to the baseball game? must go to the doctor. No, they’re not free. They Can they go to the movies? might have to meet their friends. Grammar focus 情态动词主要有:may/might, can/could, must, have to, shall/should, will/would, ought to, need, dare, used to。 现在我们来着重学习情态动词can 以及 have to 的用法。 其特征主要有: 1. 不能独立作谓语,只能和动词原形一起构 成谓语,表示说话人的语气和情态。 2. 没有人称和数的变化。 (have to除外) 3. 否定形式:在其之后加not (have to除外)。 疑问形式:情态动词提到主语之前(have to 除外)。 can为情态动词, 在本单元中表示请求, 用于发出邀请,后跟动词原形。当同意接 受对方的邀请时, 常用Sure, I’d love to. / Certainly. /Of course.等来回答;若不接受, 常用Sorry等来有礼貌地拒绝, 一般情况下 需要说明不能接受邀请的原因以表示歉意。 —Can you come to my birthday party tomorrow? 明天你来参加我的生日聚会,好吗? —Sorry, I can’t. I am going to visit my grandpa. 很抱歉,我来不了,我要去看我爷爷。 1. can/may (1) 都可表示“许可” 。may用于较正式、客 气的场合,而can比较随便(口语)。 You may/can smoke here. ? Borrowers may not take out of the library more than two books at a time. ? The policeman says you can’t park here. (2) May/Can I/we…? 表示征询对方许可。 Can you…? 表示请求。 ① — May I use your phone? — Yes, you may./Yes, please. /No, you may not. /No, you mustn’t. /No, you’d better not. /I’m afraid not. /I’m sorry. I’d rather you didn’t. ② — Can I go out and play, Mum? —Yes/Certainly, you can. /No, you can’t. ③ — Can you help me with this bag? —With pleasure./Sorry, I can’t. (3) 都可表示“可能性” 肯定句 Mr. Reed looks pale. He may be ill. (事实上的可能). Mr. Read is in poor health. He can be ill at any time. (逻辑、理论上的可能) This news may be true. (=might/could) (事实上的可能) Wang Wei can be really stubborn. (有时或偶然可能会)(=could) 否定句 This news may not be true. (也许不, =might not ) This news can’t be true. (不可能, =couldn’t) 疑问句 Can this news be true?(=Could) ≠May this news be true? (4) can 还可表示“能力”、“能够” —You can swim, can’t you? —No, I can’t. I can’t promise anything, but I’ll do what I can. Tickets can be bought from the Tourist Information Center. 2. might/could (1) 分别为may和can的一般过去时,分别表示 过去的“许可”、“可能”和“能力” 、 “能够”等。 The children aske