高中英语语法情态动词.ppt

情态动词 I am so strong that I can lift this stone. He said that Jack couldn’t finish his work in such a short time. He is only four, but he is able to read. She was able to do it without my help. Will you be able to come to my party tomorrow? You can go now. May I know your name? 3 表必须 I must go now. Since it is raining, we have to stay indoors. There must be a mistake. You may walk ten miles without seeing a house. He might get there on time. She can’t be serious. We couldn’t do better. She may not be serious. She is afraid they might not like the idea. We mustn’t waste our time. * 情态动词本身有实际词义，但不能单独作谓语，只能和后面的动词原形一起构成谓语。 We can be there on time tomorrow. 我们明天能按时去那儿。 You must obey the school rules. 你必须遵守校规。 情 态 动 词 的 定 义 情态动词无人称和数的变化，情态动词后加动词原形，否定式是在情态动词后面直接加“not”。个别情态动词有过去式，但此过去式时态性不强，可用于表示过去，现在或将来，也可用来表达委婉的语气。 情 态 动 词 的 特 点 1 表能力 can couldbe able to can表能力,但不一定能干成 ； be able to表经过一番努力设法干成了,可用于各种时态。 = manage to do/succeed in doing 2 表许可 can, may could/might也表许可，常用于问句中，表委婉 — Could I borrow your dictionary? — Yes, of course you _______. A. might B. will C. can D. should C must 表主观必须 ，没有过去式 have to 表客观必须 关于must 疑问句的回答 --- Must I come before 9 pm? --- Yes, you __________. --- No, you __________ /____________. must needn’t don’t have to 4表推测 must may might 用于肯定句中 用于否定句中表推测 can’t, couldn’t may not, might not 用于疑问句中 表推测 can could may/might 不用于疑问句中表推测 must be /can’t do/might be doing 都表对现在的推测 must have done/can’t have done/might have done 表对过去的推测 It’s 6:00.Mother _______(wait)for me outside. — He looks sad.He _________(know)the news. — No, he __________________it . must be waiting must have known can’t have known mustn’t 5表禁止 译为“一定不要…/千万别…” should/ought to 6 表应该 As a teacher, I ________ be strict with my students. should / ought to should 的另一特殊用法，译为 “竟然” You can’t imagine that a well-behaved gentlemen ___ be so rude to a lad