高中英语 Unit9 情态动词 I语法考点超级归纳素材.doc

unit9 情态动词 i语法考点超级归纳考点一：情态动词的基本用法1. 情态动词的概念情态动词又称为情态助动词（modal auxiliary）。它具有词汇意义，但意义不够完整，因此一般不能单独作谓语。情态动词表示说话人的语气和态度。2. 情态动词的特征情态动词具有以下五个特征：（1）情态动词后面一般接原形动词（即不带to的不定式）；（2）情态动词没有人称和数的变化；（3）情态动词与其他动词构成谓语时总是放在其他动词之前；（4）情态动词无非谓语形式，即没有不定式、动名词和分词形式；（5）情态动词只有现在式和过去式两种形式，但可以表示现在时间、过去时间和将来时间。3. 情态动词的意义常见的情态动词如下表所示： 情态动词词义否定式缩略否定式can / could能；能够；可能can / could notcant / couldnt may / might可以；也许may / might notmaynt / mightnt must必须；一定must notmustntshould应该should notshouldntought to 应当ought not to oughtnt to shall 可；必将shall notshantwill / would愿意；决心will / would notwont / wouldntneed需要need notneedntdare敢dare notdarent 现代英语语法还将have to, used to, had better, would rather, be going to, be about to等也都列为情态动词。考点二：表示“能力”的情态动词情态动词辨义例句can和be able tocan是最普通的用词，表示一般的能力，如凭借体力、脑力或技能去做某事；be able to比较正式，指具体的能力，尤其指通过努力才能做成某事mary can play the piano. she has been able to play it since she was five.玛丽会弹钢琴。她5岁起就会弹了。i ran as fast as i could so that i was able to get home before the heavy rain.我拼命跑，结果在下大雨前赶到了家里。考点三：表示“允许”的情态动词情态动词辨义例句can和may口语中，在表示允许或征求意见时，can与may可以互换。can / may i help you? 您要买什么？may / can i come in? 我可以进来吗？ youcan gather this information from your research. 你可以通过自己的调查搜集信息。注：问 句肯定回答否定回答may i?might i ?yes, you may / can.no, you mustnt/cant.注意：as well 在口语中常与may或might连用，作“也好，也行”或“倒不如”解，用来缓和语气。例如：you may as well go. 你去也好。the weather was so bad that we might（just）as well have stayed at home. 天气太糟糕，早知道如此，倒不如呆在家里为好。考点四：表示“推测”的情态动词情态动词辨义例句can, may和mustcan 表示可能性，可用于肯定句、否定句和疑问句，用在疑问句中暗含着某种程度的否定意义，could语气更弱；may 表示推测时，意为“也许”、“或许”，其语气相当不肯定，might语气则更弱，一般用于肯定句或否定句；must表示推测时，语气相当肯定，意为“一定”，只用于肯定句中，不能用于否定句或疑问句中。否定和疑问句中应用can。cant和may not表示否定推测。can和may表示推测时，都可用于否定句。cant意为“不可能”，may not 意为“可能不”。may/might as well，后面接不带to 的不定式，意为“不妨”。 can it be our headmaster? 那可能是我们的校长吗？ no, it cant be him. 不可能是他。that could be really exciting. 那可能真的激动人心。i think advertisements can be quite dangerous. 我认为广告可能非常有害。he may be in the library. (=perhaps he is in the library.) 他可能在图书馆。the news may not be true. 这消息可能不是真的。she might be in her office. 她可能在办公室。i think the old woman must be a nice person. 我认为那位老夫人一定是一个善良的人。he may not come today. 他今天可能不会来。tom cant be back in the united states, for i saw him at the school gate just a moment ago. 汤姆不可能回美国了，因为我刚才还在校门口见到他呢。if that is the case, we may as well try. 如果是那种情况，我们不妨一试。情态动词+进行式对正在进行的事情表示肯定推测时用must be doing 或may be doing（后者的语气不是很肯定），表示否定推测时用cant be doing。you must be joking! 你一定是在开玩笑！its twelve oclock. they must be having lunch. 现在是12点。他们一定在吃午饭。he may be waiting for you at the cinema. 他或许正在电影院等你呢。he cant be making phone calls, for the phone is broken. 他不可能在打电话，因为电话坏了。小贴士：he must be staying there.他现在肯定呆在那里。he must stay there. 他必须呆在那儿。考点五：“情态动词+have+过去分词”表示“过去推测” “can/could/may/must+have+过去分词”表示对过去情况的推测结构形式辨义例句could+have+过去分词could have done可以表示虚拟语气，说明某事本可能发生而实际并没有发生；用于疑问句时，则表示询问过去可能发生的事情。my grandparents could have lived with us. 我的祖父母本可以和我们住在一起。what could have happened? 可能发生了什么事？where can (could) he have gone?他能到哪里去了呢？couldnt+have+过去分词couldnt have done表示否定推测。he couldnt possibly have said why. 他肯定没说出个所以然来。may / might+have+过去分词may / might have done对过去发生的事情表示推测，语气不是很肯定。she may have left yesterday. 她可能昨天走了。must+have+过去分词must have done对过去发生的事情表示肯定推测，语气较强，意为“肯定，谅必”。i must have forgotten to tell you. 我一定是忘记告诉你了。注意：could, might表示推测时不表示时态，其推测的程度不如can, may。小贴士：英语中共有9个情态动词可表示推测，might表示的可能性最小，must表示的可能性最大。见下图：uncertain might that might be jack. may could canshouldought towouldwillcertain must that must be jack.考点六：表示“应该”的情态动词情态动词辨义例句must, should和ought tomust表示义务、命令或必要，意为“必须”、“应当”；should 和ought to均表示义务或责任，意为“应该”、“应当”，ought to比should语气更强，也更正式。we mustnot fall for this kind of trick! 我们决不要上这种小把戏的当！you should return this book before friday. 你应该在星期五之前还书。she shouldnt be working like that. shes still so weak. 她不应当那样干，她身体仍那么虚。his restaurant oughtto be full of people. 他的餐馆应当顾客盈门。you ought not to have told her all about it. 你不应当把这事全告诉她了。ought he to see a heart specialist at once? 他应当马上去看心脏病专家吗？must和have (got) tomust 表示说话人的主观愿望，而have (got) to 则表示客观需要，意思是“不得不”、“只好”。youmustdecide what approach you want to use. 你必须决定要采用什么样的方法。sorry ive got to go to class. 很抱歉，我得去上课了。小贴士：在否定结构中，dont have to表示“不必”，mustnt 表示“禁止”。例如：you dont have to tell him about it. 你不一定要把此事告诉他。you mustnt tell him about it. 你一定不要把这件事告诉他。注：问 句肯定回答否定回答need i?must i?yes, you must.no, you neednt/dont have to.考点七：表示“意愿”的情态动词情态动词辨义例句shall和willshall在问句中用于第一、第三人称，表示征求对方的意见，用于陈述句的第二、第三人称表示允许、命令、决心等；will表示意志、意愿、建议、决心等。shall i open the window? 我打开窗户好吗？he shall be punished if he breaks the rule. 他如果违规就应受处罚。i will take all that fat off you in two weeks if you eat here every day. 您要是每天来这儿用餐，我会使您在两周内去掉所有多余脂肪。注意：1）will you?would you like? 表示肯定含义的请求劝说时，疑问句中一般用some, 而不是any。例如：would you like some coffee?2）否定结构中用will，一般不用would, wont you是一种委婉语气。例如：wont you sit down? 3）would like，would like to do = want to do为固定搭配，意为“想要”。例如：would you like to go with me?4）would like to have done sth本打算做某事而结果并未做成。例如：i would like to have read the article, but i was very busy then.考点八：“情态动词+have+过去分词”表示“责备” “情态动词have过去分词”表示已经完成的动作或存在的状态，并带有感情色彩。情态动词结构辨义例句should have done表示过去应该做某事而未做，带有责备意味。he taught us during the lunch breaks and the evening when we should have been asleep. 他利用午餐后的休息时间及晚上本来该睡觉的时间给我们上课。shouldnt have done表示过去不应该做某事却做了，带有责备意味。we feel you should not have done that. 我们觉得你真不应该这样做。neednt have done表示过去不必做某事却做了。we neednt have hurried, as we had plenty of time. 我们不必那么匆忙，因为我们有足够的时间。ought to have done本应该做某事，而事实上并没有做，否定句表示不该做某事而结果却做了。ought to 在语气上比should 要强。there was a lot of fun at yesterdays party. you ought to have come, but why didnt you? 昨天的聚会非常有意思。你本应该来，为何不来呢？she ought not to have thrown the old clothes away. 她不该把这些旧衣服扔掉。（事实上已扔了）考点九：表示“习惯”的情态动词情态动词辨义例句will表示现在的习惯police will arrest criminals by firing nets instead of guns. 警察逮捕罪犯时，会向罪犯射网而不是开枪。would表示过去的习惯，但有可能现在仍然有，would比used to正式she would go out for a walk in the morning when she was in the country.在乡下时，她总是在早晨去散会儿步。（可能现在仍有散步的习惯）used to表示过去的习惯动作和经常的情况，现在已不复存在people used to think that the earth was flat. 过去人们认为地球是平的。（现在人们不这么认为）im 19 years old and i used to be a drug addict. 我19岁，过去是一个吸毒上瘾的人。注：1）used to与would均可表示过去的习惯动作，有时可互换。例如：he used to would smoke while writing.过去他写东西时常抽烟。2）be /get/become used to表示“习惯于”。此句型中的 used 为形容词，to 为介词, 其后跟名词或动名词，不跟动词不定式。例如: the old man is used to a simple life. 这位老人习惯过简朴生活。my mother is not used to living in big cities. 我母亲不习惯生活在大城市。考点十：兼作实义动词的情态动词need和dare用作实义动词时，像其他的实义动词一样有人称、数及时态的变化，其后可接带to的动词不定式；用作情态动词时，一般只用于否定句、疑问句和条件句。请看下表的比较：情态动词实义动词肯定he need / dare go. （较少用）he needs / dares to go.否定he neednt / darent go.he doesnt need / dare to go.肯定疑问need / dare he go?does he need / dare to go?一句多译：1. 你不必担心她。1）you neednt worry about her.2）you do not need to worry about her.2. 你竟敢这样做？1）how dare you do that?2）how do you dare to do that?3. 我的自行车需要修理。1）my bike needs repairing.2）my bike needs to be repaired.考点十一：其他词组构成的情态动词情态动词辨义例句had better固定词组，现被看作情态动词，不是过去式，而指现在或将来，意为“最好”，表示劝告或警告，其后接动词原形。you had better play one kin