专题8情态动词和虚拟语气

1、专题8情态动词和虚拟语气(二四、虚拟语气用于条件状语从句中(1表示与现在事实相反的假设,条件状语从句中的谓语动词用“过去式(be动词的过去式用were”,而主句中的谓语动词用“would / should/ could / might + 动词原形”。如:If I were a boy, I would join the army.(2表示与过去的事实相反,条件状语从句中的谓语动词用过去完成时,主句中的谓语动词则用“would / should / might / could + have +过去分词”。如:If he had taken my advice, he would have su

2、cceeded in the competition.(3表示与将来事实相反,条件状语从句中的谓语动词一般过去时或should(were to + 动词原形,而主句中的谓语动词则用would / should/could might + 动词原形。如;If it were to rain tomorrow, the football match would be put off.(4当条件状语从句表示的行为和主句表示的行为所发生的时间不一致时,动词的形式要根据它所表示的时间作相应调整。如:If they had worked hard, they would be very tired.(从句

3、说的是过去,主句指的是现在注意:有时侯在使用时可省略if,句子则可换成下列形式,即“were / had / should +主语”。如: Were I a boy, I would join the army.Had he taken my advice, he would have succeeded.五、虚拟语气用于名词性从句(1虚拟语气在宾语从句中的运用。“wish + 宾语从句”表示不能实现的愿望,译为“要是就好了”等。表示现在不能实现的愿望,从句中的谓语动词用一般过去时;表示将来不能实现的愿望,从句中的谓语动词用“would/could + 动词原形”;表示过去不能实现的愿望,从句

4、中的谓语动词用“had + 过去分词”或“could(should + have + 过去分词”。如:I wish it were spring all the year round.I wish I had known the answer.在表示建议、要求、命令等的动词suggest、advise、propose、demand、require、insist request、command、order等后的宾语从句中,谓语动词用should + 动词原形或是动词原形。如: She suggested we (shouldleave here at once.(2虚拟语气在同位语从句和表语从句

5、中的运用。作表示建议、要求、命令等的名词advise、idea、order、demand、plan、proposal、suggestion、request等的表语从句和同位语从句,从句中的谓语动词用“(should+ 动词原形”。如: His suggestion that we (shouldgo to Shanghai is wonderful.My idea is that they (shouldpay 100 dollars.(3虚拟语气在主语从句中的运用。在主语从句中,谓语动词的虚拟语气用“should + 动词原形”的结构,表示惊奇、不相信、理应如此等。如:It is neces

6、sary(important, natural, strange, etc.that we should clean the room every day.It was a pity (a shame, no wonder, etc.that you should be so careless.注意:这种从句表示的是事实。如果说人对这种事实表现出惊奇的情感,就可用虚拟语气。反之,如果不表示惊奇等情感,that从句也可用陈述句语气。如:It is pity that you cant swim.六、虚拟语气在其他场合的运用(1虚拟语气在as if/as though、even if/even t

7、hough等引导的表语从句或状语从句中,如果从句表示的动作发生在过去,用过去完成时;指现在状况,则用一般过去时;指将来状况则用过去将来时。如:He did it as if he were an expert.(2虚拟语气用于定语从句中。这种从句常用于句型“It is (hightime (that ”中,定语从句的谓语动词用一般过去时(be 用were或should + 动词原形,意思是“(现在该”。如:Its time that I picked up my daughter.(3虚拟语气用在if only引导的感叹句中。如:If only I had taken his advice.1

8、.Everyone in my class passed the exam.Oh,really?It _ difficult.(can't have been /needn't have been/must be /mightn't be【解析】can't have been 表示否定的推测应使用cant /cannot。对过去进行推测,表示“一定不”应使用cant have done。2.Some people who don't like to talk much are not necessarily shy;they _ just be quie

9、t people. (must /may/should /would【解析】may 句意为:有些人不喜欢讲话不一定是害羞,他们可能是安静的人。此处用may表示“可能”之意。3.Why didn't you answer the phone last night? I _ (sleepwhen you called.【解析】must have been sleeping 由时间状语和结合语境来看,这是对过去某个时间点正在发生事情的肯定推测,再结合题意,应该是must have been doing结构。4.When I lived with my roommates in the uni

10、versity, we _ often talk into the night.(might/must/should/would【解析】would 这里描述的是过去经常发生的动作(或过去经常做的事情。5.This is the first time I _ (takemy first picture with my own hands. It is time that you _ a picture for me.【解析】have taken This/It is the first time that中,从句的谓语动词通常用现在完成式;6.Why hasn't Jack come b

11、ack yet?Can anything have happened to him?I'm not sure, but I guess something _(have.【解析】may have 推测发生过的事情时情态动词后要接完成式。7.Liza_ well not want to go on the trip she hates traveling.(will/can/must /may【解析】may .may well (not do sth.意为“很可能(不干某事,完全(没有可能干某事”。8.The soccer team has been doing well this se

12、ason,so they _ win the championship.(should/might/would/must【解析】should句意为:这个足球队在这个季度训练得很好,因此,他们应该会赢得冠军。根据常理进行推测表示“应该”时用should。9.What does the sign over there read? No person _ smoke or carry a lighted cigarette in this area.(will /shall /may /must【解析】shall. 答句句意为:任何人在这里都不能吸烟或者是携带点燃的香烟。Shall在这里表示强制,用

13、于法令、条约、规章中,意为“必须,应该”。10.For environmental reasons,we _ as well take these waste products and have themrecycled.(should/would/might /could【解析】might. 所填词与as well构成固定搭配,意思是“不妨,还是为好”用may/might.11.We _ (behere at lunch time; we were delayed at the airport, though.【解析】would have been .would have done sth.

14、表示与已经发生的事实相反,意思是“本来会但实际没有”。句意为:我们本来能在午餐时到达,但我们在机场被延误了。12.You _ buy a gift,but you can if you want to.(must /mustn't/have to/don't have to【解析】don't have to。dont have to意为“没有必要”,符合语境。句意为:你没有必要买礼物,但如果你想买的话,你也可以买。13. May I take this book out of the reading room?No,you_. You read it in here.(

15、mightn't /won't /needn't /mustn't【解析】mustn't 本题考查情态动词的用法。表示“禁止;千万别做某事”时,要用mustn't。14I havent got the reference book yet,but I'll have a test on the subject next month.Dont worry. You _have it by Friday.(could /shall/must /may【解析】shall当主语为第二、三人称时,情态动词shall表示说话人给对方命令、警告、允诺或

16、威胁,本句表示允诺。15.George is going to talk about the geography of his country,but I'd rather he _ (focusmore on its culture.【解析】focused 。would rather+从句,从句表示对现在或将来虚拟时应使用一般过去时。16.Just be patient. You _ expect the world to change so soon.(can't /needn't/may not /will not【解析】can't 句意:耐心一点儿, 你

17、不能期望世界变化如此快。通过选项此题考查情态动词, cant在否定句中可以表示推测, 译为不可能,可以表示能力, 译为不能够,语气强烈。也可以表示命令, 不允许, 但是语气比mustnt弱, 具有劝慰的意思, 根据句意此题中选择A, cant表示劝慰。17.Teachers recommend parents _ (not allow their children under 12 to ride bicycles to school for safety.【解析】not allow 。句意为:教师们建议:为了孩子们的安全,父母不应让12岁以下的孩子骑自行车去学校。recommend意为“建议

18、”,其后接的宾语从句采用虚拟语气,从句谓语动词用“should+动词原形”的形式,should可以省略。18.Mark _ have hurried. After driving at top speed,he arrived half an hour early.(needn't /wouldn't/mustn't /couldn't【解析】needn't.needn't have done 本没有必要做某事,实际上做了。句意:迈克本来不必要那么忙的。这么高速驾驶之后, 他早半个小时到达了。根据后面的语境, 提前半个小时到达, 说明Mark本来不必那么匆忙, 所以用neednt have done 结构, 表示“本来不必要做某事的而实际上做了”。19.I _ have watched that movie it'll give me horrible dreams.(shouldn't /needn't /couldn't /mustn't【解析】shouldn't shouldn't have done意为“本不应该做但实际已经做了(表达后悔的