情态动词和虚拟语气

第 1 页 2020 3 28 情态动词和虚拟语气情态动词和虚拟语气 备课者 丁杰 常考点清单 情态动词的类型和特征 情态动词的类型 一 情态动词有 must can could may might ought to had better shall should will would have has to used to need dare 二 情态动词的特点 1 有一定的词义 但不能单独作谓语 他们要和行为动词或连系动词连用 构成谓语 后面接动词原形 2 没有人称和数的变化 除了 have to 以外 3 情态动词一般有时态变化 除 must ought to 以外 常考点清单二 情态动词用法要点 一 表能力 can be able to 1 can 有两种时态 can could 2 be able to 有更多的时态 was were able to will be able to have been able to 3 表示过去有能力并且成功地做了某事 要用 was were able to 相当于 succeeded in doing something manage to do sth 而不能用 could 二 表推测 可能性 can could may might must should ought to 1 can could 常有于否定句和疑问句 may might 常用于肯定句和否定句 must should ought to 用于 肯定句 2 在肯定句中 may 表示 可能 must 表示 一定 准是 在否定句中 can t 表示 不可能 may not 表示 可能不 比较 He must be in the classroom for I saw him just now He can t be in the classroom now for I saw him play basketball on the playground He may might not be in the classroom but I am not sure 3 can 也可以用于肯定句 但表示客观理论上的可能性 may 用于肯定句中 表示具体理论上的可能性 结 构 can may must have done be doing do something Tigers can eat man Accidents can happen on such rainy day Everyone can make a mistake The part of the country can be very warm in September 4 must 表推测用于肯定句 否定句用 can t couldn t 5 must have done must do something must be doing something 的反意疑问句与 must 后面的动词保持 一致 He must be kidding isn t he You must be kidding aren t you He must have finished his homework hasn t he You must have finished your homework yesterday didn t you He must be helping the old man to water the flowers B 2009 陕西卷 A is he B isn t he C must he D mustn t he Hi Tom Any idea where Jane is 2009 重庆卷 She C in the classroom I saw her there just now A shall be B should have been C must be D might have been 6 must 表示 偏要 硬要 做某事 How old are you madam If you must know I m twice my son s age If you must smoke please go out Must you make so much noise 你非得弄出这么大的声响吗 三 表示必要性 must have to 第 2 页 2020 3 28 1 must 表 必须 是主观上的认识 Must I clean all the room Yes you must No you needn t No you don t have to May I use your dictionary Yes you may No you mustn t 委婉的拒绝可用 Sorry but I am using it Now 或 You d better not 2 have to 表 不得不 是客观上的认识 don t have to don t need to do something needn t do something 四 表示请求 允许 允诺 1 shall 用于第一称或第三称的疑问句 用于征求对方意见 结构是 shall I we he she they Shall we go to the movie tonight Shall the driver wait outside 司机在外面等着可以吗 2 shall 用于陈述句中的二 三人称 表许诺 命令 警告 威胁等 You shall have this book tomorrow You shall not have the computer if you don t take good care of it 3 当宣布法律 法规的规定时 也要用 shall 4 Could Might I borrow your dictionary Yes of course you can may No I m afraid not 不可说 Yes you could might 回答允许时 用 could might 表委婉是不恰当的 五 had better should ought to 的用法 这三者都可以用来提建议 语气强弱顺序 had better should ought to should ought to 的用法 1 常用来表示因为有责任 义务 而应该做某事 如 You shouldn t leave a baby alone in the house The students ought to obey the school rules 2 表示劝告或建议 应当 宜于 如 He should stop smoking 3 表猜测 理应 按理说应该 总应该 如 If he started at seven he ought to should be here now How s your tour around the North Lake Is it beautiful It should be but it is now heavily polluted When can I come for the photos I need them tomorrow afternoon They should be ready by 12 00 4 should 还有 竟然 竟会 的意思 表 惊讶 愤怒 等情绪 Why How should 表示 竟会 怎么会 Why should you be so late today How should I know You can t imagine that a well behaved gentleman should be so rude to a lady 六 would 的用法 1 过去将要 2 过去常常 3 表决心 决意 过去的意愿 He promised the teacher that he would not smoke again Why didn t you come to Simon s party last night I wanted to but my mom simply C not let me out so late at night A could B might C would D should 4 交际用语中表达请求 许可 语气客气 委婉 Would you do me a favor 请帮我一下 好吗 七 will 的用法 1 表意愿 Write to me when you get home I will I will help you 2 现在或将来的习惯 The old man will sit by the window for hours 3 临时作出的决定 I heard our teacher was ill Well I will see him this afternoon 第 3 页 2020 3 28 Ann is in hospital 2009 江苏卷 Oh really I D know I go and visit her A didn t am going to B don t would C don t will D didn t will 4 表示必然的趋势 Fish will die without water Human beings will not survive without air 八 情态动词 have done 用法一览表 情态动词 完成式用法 例句 must have done 表示对过去发生的动作进 行肯定的推测 意为 一 定 准是做了某事 It must have rained last night for the ground was wet I didn t hear the phone I must have been asleep could can not have done 表示对过去发生的行为的 怀疑和不肯定 意为 不可 能发生了某事 He can t have turned up at the party for he went abroad could have done 表示 本来可以做某事 却没有做 You could have helped him may might have done may might not have done 表示 过去可能做过某 事 但不肯定 或 过去 可能没有做过某事 不用 于疑问句 It s too late He may have gone to bed He might not have finished the work should ought to have done shouldn t oughtn t to have done 用于肯定句时 表示 本 该做某事 而实际上没做 用于否定句时 则表示 不该做的事却做了 You should have come to the meeting earlier You shouldn t have told her the truth She is sad now The plant is dead You should have given it more water needn t have done表示 做了本没有必要做 的事 却做了 You needn t have taken a taxi here for it was very near to my house had better have done 用于事后的建议 含轻微 责备的口吻 意为 当时 最好做了某事就好了 You had better have started earlier would rather have done表示 当时最好做了某事 就好了 I would rather have taken his advice would like love to have done 表示过去愿意做某事 但 未做 I would love to have gone to the party last night but I had to work extra hours to finish a report 九 情态动词其他用法要点 1 could can not but do sth 表示 不得不 只好 I could not but choose to go 2 may well do sth 表示 很可能 相当于 be likely to do sth 3 may as well do sth 意为 最好 倒不如 You may as well do it at once I have nothing to do so I may as well go to bed 4 can not never enough too 表示 再 也不为过 越 越 好 5 need dare 的用法 need 和 dare 两者即可用作情态动词也可用作行为动词 通常用于否定句和疑问句中 He needn t walk so fast He doesn t need to walk so fast I daren t ask her for a rise 我不敢请求她加薪 How did you dare to tell her that I wonder whether he need send it immediately 第 4 页 2020 3 28 You needn t finish that work today I dare say 是习惯用法 意为 我想 大概 need 作为行为动词时 还可表示 需要 后接动名词主动形式表示被动含义 The garden doesn t need watering at the moment 部分情态动词的否定式是情态动词中的考点之一部分情态动词的否定式是情态动词中的考点之一 mustn t 不准 禁止 needn t 没必要 don t have to can t 不能 不可能 may not 不可以 可能不 shouldn t 不应该 ought not to 常考点清单三 虚拟语气 一 虚拟语气在非真实条件句中 虚拟条件句 if 主句例句 与现在事实相反的假 设 did wereshould would could might 动词原形 If I were you I would go with her 与过去事实相反的假 设 had doneshould could 等 have done If you had taken my advice you would not have failed in this exam 与将来事实相反的假 设 did were to do should do should would could might do If it were to rain tomorrow the sports meeting would be put off 使用虚拟条件句时要注意以下几点 1 错综时间虚拟语气 主从时间不一致 要对应各自的形式 If you had studied hard before you would be a college student now If it hadn t rained last night it would be very warm today 2 如果条件句中有 were had should 这三个单词时 可把 if 省略 把这三个单词放在句首 变为倒装句 式 Were I you I would take his advice Had I been there then I would have helped her Should he come tomorrow I would have a word with him 3 介词 with without but for 用于虚拟语气中 介词短语代替条件状语从句 Without sunlight there would be no living things on the earth But for your help we could not have finished the work ahead of time But for their help we D the program in time 2009 安徽卷 A can not B will not C had not finished D could not have finished 4 含蓄条件虚拟语气 I was ill that day Otherwise I would have taken