情态动词讲义

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.（1） can 能够,会,可以，表示现在的能力 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 cant be our English teacher because she has gone to Shanghai . Can it be true ?,（2）could表示过去的能力,（3）be able to 表能力，可用于多种时态 强调成功的做成了某事,2. may 可以,可能,也许 Eg: You may go with me . - May I borrow your pen ? - Yes , you may . No , you _,cant / mustnt .,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 dont know. _he can tell you. 2) I dont know. He _tell you .,Maybe may,3. must 必须 mustnt 严禁,禁止,不许 Eg: I must learn how to work . You mustnt play in the street . - Must I finish the work now ? - Yes , you must . No, you neednt / dont 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 dont . 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: Its eleven oclock . I have to go now . He has to finish the work first . 请注意: I dont have to go now . He doesnt 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 its 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. Youd better do sth 你最好做某事 Eg: Youd better buy the book . Youd better not do sth 你最好不要做某事 Youd better not run in the classroom .,