专升本英语语法之虚拟语气重点总结

　　专升本考试英语语法重点，虚拟语气考试重点：虚拟语气的基本形式和用法；if的省略形式；含蓄条件句；以wish（that）引导的表示“愿望”的宾语从句；would rather 引导的从句；以as if, as though 引导的从句；以suggest, advise, insist 等词后引导的宾语从句；It is necessary（important）that引导的主语从句；It is time （that）…句型中。
　　（一）虚拟语气的基本形式和用法：
　　虚拟（条件）语气中，主句与从句中谓语动词的形式可分为下面三类：
　　1、I would ask George to lend us the money if I _____ him.A. had knownB. have knownC. knewD. know
　　[解析] 正确答案A。本题测试的是错综虚拟条件句。条件是与过去事实相反的假设，结果是与现实相反的结果。与过去事实相反的假设条件句用过去完成时，与现实相反的主句用“would/should/could/might 动词原形”。
　　2、Do you think there would be less conflict in the world if all people _____ the same language?A. spokeB. speakC. had spokenD. will speak
　　[解析] 正确答案A。do you think是主句，后面的部分是宾语从句，而宾语从句是一个包含if 条件状语从句的复合句；there would be判断, if从句中可以用一般过去时spoke，表示现在事实的虚拟。句意为; 你如果认为人们都说同样的语言，世界上就会少些冲突吗？
　　3、If Bob____ with us, he would have had a good time.A. would comeB. would have comeC. had comeD. came
　　[解析] 正确答案C。与过去的事实相反，从句的谓语动词用过去完成时。
　　（二）if的省略形式
　　在虚拟条件句中， 如谓语包含were , had, should等词， 则可以把这些词放到主语前面，省略if。
　　1、_____ you were busy, I wouldn t have bothered you with my questions.
　　A. If I realized B. Had I realized
　　C. Did I have realized that D. As I realized
　　[解析] 正确答案B此句为与过去事实相反的虚拟句，条件上句用的是if I had realized you were busy的倒装形式。
　　2、_____, I should ask them some questions.
　　A. Should they come to us B. If they come to us
　　C. Were they come to us D. Had they come to us
　　[解析]正确答案A。本题测试虚拟语气的用法。虚拟语气中的状语从句可以省略if从句中的助动词had，were，should等要移至主语之前，即用半倒装语序。例如：Should it be summer, I would go swimming．本句的意思是：“如果他们来到我们身边，我就会问他们一些问题。”
　　（三）含蓄条件句有时一个假设的情况不用条件从句表示，而用其它方式来表示，这样的句子叫含蓄条件句。常用with，without，but for。
　　1、Without your help, we _____ so much.
　　A. didn’t achieve B. would not have achieved
　　C. will not achieve D. don’t achieve
　　[解析]正确答案B。此句检测虚拟语气的使用用法。without your help是一种与事实相反的表达方法，句末so much则说明动作已经完成，故应该用与过去事实相反的虚拟语气。
　　2、But for the rain, we _____ a nice holiday.
　　A. should have B. would have had C. would have D. will have had
　　[解析]正确答案B。虚拟语气。But for要不是，假如没有，其后的句子应该用虚拟语气。如：But for these interruptions， the meeting would have finished earlier．要不是有人打断，会议肯定可以早点结束。
　　（四）以wish（that）引导的表示“愿望”的宾语从句wish后的宾语从句中要用虚拟语气，而在虚拟语气中时态的应用类似在非真实条件中从句时态的应用。表示现在或将来的愿望用：主语＋wish ＋从句（主语＋过去时）；表示一个过去没有实现的愿望用：主语＋wish 从句（主语＋过去完成时）；
　　1、Peter wishes that he _____ law instead of literature when he was in college.
　　A. could study B. studied C. had studied D. would study
　　[解析] 正确答案C。本题测试虚拟语气。wish后面的宾语从句要使用虚拟语气，虚拟语气的时态类似在非真实条件从句中时态的应用――时态后移。表示与现在的事实相反(用过去时)：I wish I were you. (但愿我是你多好啊!)表示与过去的事实相反的愿望(用过去完成时)：I wish he hadn't made the big mistake. (他要是不犯那个大错误，该有多好!)表示与将来的愿望相反，即愿望难以实现(用过去将来时)：I wish I would be of more use in the future. (我希望我将来有点用处。)
　　2、I didn’t go to the party, but I do wish I _____ there.
　　A. were B. would be C. had been D. will be
　　[解析] 正确答案C。考查虚拟语气。wish的虚拟语气，对过去时的虚拟后面用过去完成时表示。
　　（五）would rather＋句子（过去时）
　　1、I’d _____ you didn’t touch that, if you don’t mind.A. ratherB. betterC. happierD. further
　　[解析] 本题测试“would rather”的用法。本句的意思是：“如果你不介意的话，我宁愿你别碰那个。”would rather的意思是“宁愿，更喜欢”。例如：I would rather early set out. (我宁愿早出发。)所以答案是A
　　2、I am too busy these days. I would rather all of you _____ next month for a dinner.A. comeB. would comeC. cameD. have come
　　[解析] 正确答案C。注意would rather someone did something是虚拟语气的一个重要考点；应该熟记。其他时态不能在这个句型中使用。
　　（六）以as if，as though引导的从句在as if，as though引导的从句中，如果谈论的是不可能或不真实的情况时，它们所引用的状语从句要用虚拟语气，动词形式和wish 后面的从中动词形式变化相同。
　　1、He talks as if he _____ everything in the world.A. knowsB. knewC. had knownD. would have known
　　[解析] 正确答案B。本题测试as if 引导的虚拟语气。当谈论现在的情况时，用一般过去时。例如：He talks as if he were the president．
　　（七）以suggest，advise，insist等词后引导的宾语从句中，从句的谓语动词要用should 动词原形，should可以省略。类似的动词有：propose，order，demand，require，request等。
　　1、The doctor advised that Mr. Malan __ an operation right away so as to save his life.
　　A. had B. would have C. have D. was going to have
　　[解析] 正确答案C。本题测试advise引导宾语从句的用法，从句要用虚拟语气，形式为“(should) 动词原形”。类似的动词还有：suggest，insist， order等。
　　2、His mother insisted that he _____ the coat when going out.A. put onB. puts onC. to putD. putting on
　　[解析] 正确答案A。本题测试虚拟语气的用法。由insist引导的宾语从句，要用虚拟语气，形式是“(should) 动词原形”，should可以省略。例如：I insist that you(should)be present．(请您务必到场。)本句的意思是：“他母亲坚持要他外出时穿上大衣。”
　　（八）It is necessary/important/urgent that引导的主语从句中，从句的谓语动词要用should 原形动词，should可以省略。
　　1、It’s desired that she _____ to teach us at least twice a week.
　　A. comes B. will come C. come D. may come

　　[解析] 正确答案C。本题测试虚拟语气的用法，在suggest，ask，decide， desire等词表示建议、请求或命令的意思时，其后所跟的从句动词形式为“should 动词原形”，should可以省略。例如：Her teacher suggested that she (should)stay at home for a month for the sake of her health．本句的意思是：“她被要求每周至少教我们两次课。”
　　2、It’s urgent that a meeting _____ before the final decision is made.
　　A. will be arranged B. must be arranged
　　C. be arranged D. would be arranged
　　[解析] 正确答案C。It is(was) 形容词/过去分词 that...结构中形容词后的主语从句用虚拟语气表示愿望、建议、请求、命令、可能、适当、迫切、重要等；should可省略。常用的形容词由natural，appropriate，advisable，preferable，better，necessary，important， imperative，urgent，essential，vital，probable，possible，compulsory，crucial，desirable等。
　　（九）It is time (that)…引导的定语从句中，谓语动词用过去时。
　　1、It’s high time we _____ something to stop traffic accident.
　　A. do B. will do C. did D. must do
　　[解析] 正确答案C。虚拟语气。It is (high)time that后面的从句谓语动词要用过去式或“should 动词原形”，但should不可省略。选项C符合此结构要求。
　　2、Don’t you think it is time you _____ smoking?
　　A. give up B. gave up C. would give up D. should give up
　　[解析] 正确答案B。本题测试“it is time...”的语法。“It is (high) time... ”表示“是……时候了”，后面从句的谓语动词要用过去式。例如：his time that we went to bed. (是我们睡觉的时候了。)本句的意思是：“你不认为该是你放弃吸烟的时候了吗 ”。