1、2情态动词的虚拟用法每个情态动词都有很多的意思和不同的用法，除了它们的基本用法之外，有些情态动词还具有一个相同的用法表示与所说的事实相反，即虚拟用法。本节课老师就和同学们一起来看看这几个情态动词的虚拟用法。下面这些情态动词后面接have done, 表达的是一种与事实相反的意思。一. 结构和含义1. should have done sth.本应该做某事（但实际上未做）ought to have done sth.shouldnthavedonesth.本不该做某事（但实际上却做了）oughtnttohavedonesth.There was a lot of fun at yesterday
2、s party. You should/ought to have come, but why didint you?昨天的舞会非常有趣。你本应该来的，但是你为什么没来呢？I tried to play with a bad injury and I shouldnt have done that.我曾经尝试着带着严重的伤势去比赛，我当初真不该那么干。She ought to have seen a doctor about her headache a week ago.她本应一周前去看头痛病的。You ought not to have taken the book out of the
3、reading-room.你本不应该把书带出阅览室。2. could/might have done sth. 本可以做某事（但实际上未做）I could have been a doctor, I could have been a lawyer, but I choose to be a teacher.我本可以成为一名医生，本可以成为一名律师，但我选择了做一名教师。If he had taken the doctors advice, he might have already recovered from his illness.如果他听从了医生的建议的话，他的病可能已经好了。3.ne
4、ednt have done sth. 过去本来没有必要做某事（但实际上却做了）I dressed very warmly for the trip, but I neednt have done so. The weather was hot.旅行时，我衣服穿得较多，其实没有必要. 那时天气很热。You neednt have apologized to her. It was not your fault.你本不必向她道歉，那不是你的错。You neednt have watered the flowers, for it is going to rain.你本不必浇那些花，因为就要下雨了
5、。拓展：didnt need to do sth. 表示过去没有必要做某事，实际上也没有做I didint need to get up early this morning, so I stayed in bed until 9 a.m.今天早上我没必要早起，所以我一直睡到上午9点。We didnt need to worry about tickets or reservations. The travel agency jacked the whole thing up for us.我们不必为车票或预定房间的事操心。旅行社会为我们把一切都安排妥当的。二. 典型例题：1. Oh, Im
6、not feeling well in the stomach. I _ so much fried chicken just now.A. shouldnt eat B. mustnt have eaten C. shouldnt have eaten D. mustnt eaten答案：C解析： just now是表示过去的时间状语。情态动词在表示过去发生的事时，必须用情态动词+have+过去分词的形式。所以只能在选项B或C中确定答案。mustnt have eaten是一个错误选项，因为mustnt+动词表示禁止，不表示判断或推测。shouldnt have done sth.意为“本不
7、应该做某事（但实际上做了）”句意：噢，我觉得胃不舒服。我刚才不应该吃那么多炸鸡。解题思路：如果一件事情发生在过去，使用情态动词时，需要使用“情态动词+have done”的结构；这种结构使用的时候需要牢记表示虚拟的那些情态动词形式。2. I _ here in time, but I met an old friend of mine. I stopped and talked with him for some time. A. shouldnt have come B. could have comeC. neednt have come D. must have come答案：B解析：s
8、houldnt have done意为“本不应该做某事而做了”； could have done意为“本可以做某事而未做到”； neednt have done意为“本没有必要做某事而做了”； must have come表示对过去发生的情况的肯定推测，意为“过去一定发生了某事”。句意：我本可以及时到这儿的，但是我遇见了一位老朋友。我停下和他聊了一会。解题思路：如果一件事情发生在过去，使用情态动词时，需要使用“情态动词+have done”的结构；这种结构使用的时候需要牢记表示虚拟的那些情态动词形式。3.As it turned out to be a small house party, w
9、e_so formally.A. neednt dress upB.did not need have dressed upC.did not need dress upD. neednt have dressed up答案：D解析：neednt have done sth.意为“过去本来没有必要做某事，但实际上却做了”。need如果做实义动词，用法为need to do sth.所以BD两项的结构不正确。句意：结果发现这是个小的家庭聚会，我们本没有必要穿的如此正式的。解题思路：首先判断出need是实义动词还是情态动词；方法1：根据否定的形式可知，直接加not的为情态动词，need前面使用助动
10、词加not，此处need为实义动词；方法2：观察need本身的形式和时态。如果need本身使用了单数第三人称形式或其他时态形式，说明此处need为实义动词；做情态动词用的need没有人称和时态的变化方法3：观察need后面所接动词的形式。情态动词need后接动词原形，实义动词need后接不定式。根据need的词性和句意判断是否应该使用虚拟的形式。三. 总结：熟记这些情态动词的用法，注意与事实的对比情态动词意义should have done sth本应该做某事（但实际上未做）ought to have done sth.shouldnthavedonesth.本不该做某事（但实际上却做了）ou
11、ghtnttohavedonesth.could have done sth.本可以做某事（但实际上未做）might have done sth.neednt have done sth.过去本来没有必要做某事（但实际上却做了）didnt need to do sth.表示过去没有必要做某事，实际上也没有做四. 巩固练习1. I was really anxious about you .You_ home without a word.A. mustnt leave B. shouldnt have leftC. couldnt have leftD. neednt leave2. 【201
12、5天津卷】I _ have worried before I came to the new school, for my classmates here are very friendly to me.A. mightntB. mustntC. needntD. couldnt3.【2015福建卷】-Sorry, Mum! I failed the job interview again.-Oh, its too bad. You _ have made full preparations.A. mustB. canC. wouldD. should4. We _ the difficult
13、y together, but why didnt you tell me?A. should face B. might face C. could have faced D. must have faced5. We _ have bought so much food now that Suzie wont be with us for dinner.A. may not B. neednt C. cant D. mustnt6. 【2014年湖北卷】完成句子 阅读下列各小题，根据汉语提示，用句末括号内的英语单词完成句子。1). The community college has to
14、cut down on staff _.(save)为了省钱，那所社区学院只好裁员。2).So far the well-known journalist _ more than 4000 interviews with famous people.(accumulate)迄今为止这位著名记者采访名人已累计达四千余人次。3). Sometimes _ to use examples to explain abstract concepts.(helpful)有时候举例也许有助于解释抽象的概念。4). The police will reward _ useful information to
15、catch the robber.(provide)任何人提供有用信息帮助抓住劫匪，警方将予以奖励。5). Hes the only student in the class _ to take part in the Model United Nations conference.(select)他是班上唯一被选上去参加模拟联合国大会的同学。6). No other technological development has had _ as the growth of electronics on so many aspects of social, economic, and cultu
16、ral development.(impact)没有哪项技术的发展像电子技术这样，对我们的社会、经济以及文化等诸多方面产生过如此重要的影响。7). You _ the meeting to tell me that; you could have come to tell me afterwards.(interrupt)你不该打断会议来告诉我那件事，你本可以会后告诉我。8). This novel was once the _ book in high schools in the United States.(read)这部小说曾经是美国高中阅读最广泛的书。9). The Public S
17、quare is an eye-catching sight of the city._ many stone sculptures of famous historical figures.(stand)大众广场是这个城市引人注目的景点，许多历史名人的石雕像矗立在那儿。10). It was several minutes _ what he was saying.(take)过了好几分钟，我才理解他说的是什么。7. 【2012年江西卷】We _ have bought so much food now that Suzie wont be with us for dinner.A. may
18、 notB. needntC. cantD. mustnt参考答案和解析：1. 答案：B解析：should t have done表示本来不应该做而做了，含责备意味。mustnt+动词表示禁止句意：我真为你着急，你本不应该不说一句话就离开了家。2. 答案: C3. 答案: D4. 答案: C解析：由“but why didnt you tell me”可以得知说的是过去的情况，所以应该使用“情态动词+have done”的结构，排除AB两项。 could have done意为“本可以做某事而未做到”；must have come表示对过去发生的情况的肯定推测，意为“过去一定发生了某事”。由后
19、一句可以推测“我们并没有一起面对困难”，所以D项意思不对。句意：我们本可以一起面对困难的，但是你为什么没有告诉我。5. 答案: B解析：may not have done意为“过去也许没有做某事”； neednt have done 意为“本没有必要做某事而实际上做了”；cant have done意为“过去不可能做了某事”；mustnt意为“禁止”；由句意可知应该使用neednt have done句意：我们本没有必要买那么多的食品的，因为Suzie不和我们一起吃晚餐。6. 答案:1). (in,order) to save money/so as to save money2). has
20、accumulated3). it might/may be helpful4). whoever provides/has provides5). that has been selected6). such a great impact/as great an impact7). shouldnt/oughtnt to have interrupted8). most widely read9). There stand10). before I could take in/before I took in7. 答案：B解析：考查情态动词和虚拟语气。句意: 既然Suzie不会和我们在一起吃晚饭,我们就没必要买那么多食物。neednt have done sth. 表示“过去本不需要做某事而实际上已经做了” 符合语境。故选Bmay not have done sth.表示“过去也许做了某事”；cant have done sth. 表示“过去不可能做了某事”；mustnt意为“禁止”版权所有：高考资源网()