一、大学英语四级常考语法点（虚拟语气和倒装）1.虚拟语气在条件句中的用法条件从句中的谓语主句谓语与现在事实相反V.-ed(be→ were)Would/should/could/might +v.与过去事实相反Had doneWould/should/could/might + have done与将来事实相反v.-ed (be → were)/Should + v./were to +v.Would/should/could/might +v.2.一些特殊的虚拟条件句1）Conditional Sentences of Mixed Time （错综时间条件句）：If you had taken her advice, you wouldn’t be in such trouble now.（if从句说的是与过去事实相反，主句说的是与现在事实相反）If it hadn’t been for the doctors’ care, I wouldn’t be speaking to you now.注：如果if 从句中的谓语动词是had, should, were,可以省掉if, 分别把这三个词提前，其余成分保持不变。
如：上述第二句had it not been for the…2) Sentences of Implied Condition （含蓄条件句）：(由but, otherwise等一些词引导)But for my money that woman would have persecuted him.I would have written before but I have been ill.In the old days she would have argued.Given more time and money, he would have done better than what it is.Electronic computers must be made very small. Otherwise it would be impossible for them to be put in a satellite.3. 虚拟语气在某些从句中的运用1）在宾语从句中的运用A. wish后的宾语从句：（往前面推一个时态）用过去式表示现在情况：I wish I knew what was going to happen.I wish I could help you.用过去完成时表示过去的情况：My father wishes that he had gone to university. （不看wish这个单词本身的时态，看整个句子暗示的发生时间，再往前面推一个时态）注：间或用would构成谓语：I wish you wouldn’t be so noisy.B. would rather/sooner; had better; suppose后的宾语从句（that引导，that可以省掉）I would rather you told me the truth.I’d sooner you didn’t ask me that question.I had better you did it.Suppose her father turned her out of doors!C.用在某些动词后的宾语从句：suggest,（建议用虚拟，暗示不用） demand, insist,（坚持要求用虚拟，坚持认为不用） ask, propose, urge, vote, request, command, desire, move, order, recommend, require,decree, intend, petition, decide, direct + that + (should) + v.He suggested that a petition (should) be drawn up.His pale face suggested that he was ill.He insisted that he (should) be sent because he insisted that he was innocent.2)虚拟语气在主语从句中的运用Advisable, appropriate, desirable, essential, fitting, imperative, important, impossible, necessary, obligatory, proper和一些表示感情色彩的形容词unfair, dreadful, strange, surprising, natural, unthinkable, unbelievable. （should加动词原形，should可以省掉）It is essential that all the facts be examined first.It is necessary that he come back without delay.3)用在表语从句和同位语从句中：（就是上面的一些形容词、动词转化为名词）Sophia’s idea was that they (should) lock up the house.The resolution that women be allowed to join the society was carried.4)用在状语从句中：A. As if/as though（往前面推一个时态）表示现在的情况用过去式：I remember it vividly as though it were tonight.He behaves as if he owned the place.表示过去的情况用过去完成时：He talked about Rome as though he had been there himself.B.目的状语从句Lest, in order that, so that, for fear that, in caseHe hurried on, lest she should meet him again.5）用在It’s (high) time后的定语从句中（可以用should加动词原形）It’s high time we went.It’s time we ordered dinner.Inversion状语前置常引起倒装1.Full Inversion: 整个谓语位于主语之前a. 当句首状语为方位词，谓语动词为go, come等表示位置转移的动态动词时。
