中考英语复习课件17-情态动词.ppt

* 情 态 动 词 　常见的情态动词有 can , could , may , might , must , need , have to , should 等. 所有的情态动词后面都接动词原形. Eg: I can swim . He has to go now . 1. can 能够,会,可以 Eg: I can speak English well . Can you tell me how to start the machine? 此外, can 用来表示否定推测和疑问推测 Eg: That can’t be our English teacher because she has gone to Shanghai . Can it be true ? 2. may 可以,可能,也许 Eg: You may go with me . --- May I borrow your pen ? --- Yes , you may . No , you _______________ can’t / mustn’t . 此外, may 表示可能时注意和 maybe 的区别 maybe 可能(副词),不能做谓语,常在前面 Eg: Maybe you know the old man . = You may know the old man . may 常放在句中,和动词原形一起做谓语 1) I don’t know. _______he can tell you. 2) I don’t know. He ______tell you . Maybe may 3. must 必须 mustn’t 严禁,禁止,不许 Eg: I must learn how to work . You mustn’t play in the street . --- Must I finish the work now ? --- Yes , you must . No, you needn’t / don’t have to(不必）. 此外 must 用于肯定推测,表示 肯定是 Eg: The book must belong to him because we can see his name on it . 4. need 需要 既可以做实义动词也可以 做情态动词 实义动词 need to do sth 需要做某事 Eg: I need to buy a big house . --- Do you need to buy a big house ? --- Yes , I do . No, I don’t . He needs to borrow a map . --- Does he need to borrow a map ? 2) 情态动词 need do sth 需要做某事 Eg: I need buy a big house . 5. have to 不得不 Eg: It’s eleven o’clock . I have to go now . He has to finish the work first . 请注意: I don’t have to go now . He doesn’t have to finish the work first. have to 和 must 的区别: have to 表示客观因素 Eg: We are very glad at the party , but it’s 11 , so we have to leave now . must 表示主观因素 Eg: We must study hard to find a good job for ourselves . 6. You’d better do sth 你最好做某事 Eg: You’d better buy the book . You’d better not do sth 你最好不要做某事 You’d better not run in the classro