高中英语语法专项讲义：虚拟语气

虚拟语气 一 虚拟语气在含非真实条件句的主从句中的应用 1． 表示与现在事实相反的虚拟语气 在表示与现在事实相反的虚拟语气句子中，if从句的谓语动词须用一般过去时（动词为be时，各人称都用were），主句的谓语动词须用“would（第一人称也可以用should）+动词原形”。 If I were you，I should try the other method. If there were no plant，there would be no life. If they had time now，they would come and join us in the discussion. 根据句意需要，if从句中有时也可以用过去进行时。 If it were not raining so hard，I would let you go. if从句中的be不管人称如何一般都要用were，但是现在也有在第一、三人称单数时使用was的倾向 尤其是在会话中。 I would not mind if he was not so rude. 在正式文体中，仍然使用were。在“if I were you”句型中，不能将were改为was。 2． 表示与过去事实相反的虚拟语气 在表示与过去事实相反的虚拟语气句子中，if从句的谓语动词须用过去完成时，主句的谓语动词用“would（第一人称也可以用should）+have+过去分词”。 If you had taken my advice，you would not have made such a mistake. If I had been you，I should have tried the other way. 根据句意的需要，if从句中有时也可以使用过去完成进行时。 If he had not been working hard night and day，he would not have made such great achievements. 3． 表示与将来事实相反的虚拟语气 在表示与将来事实相反或实现的可能性较小的虚拟语气句子中，if从句的谓语动词须用“should+动词原形”（实现的可能性中等），也可以用“were to+动词原形”（实现的可能性最小），或者动词的一般过去时（实现的可能性最大）。 If it should rain tomorrow，what would you do？ If I were to do it，I should do it some other way. If you did that again，we would not allow you work with us. 4． 带could，might的虚拟语气 在表示虚拟语气的句子中，不论是从句还是主句都可以用could和might等情态动词。 If I could repair the TV set，I should be glad to help you. If he were to tell us everything，we could try to solve his problem. She might have come if she had not been so busy. 5． 虚拟条件从句的倒装 在表示虚拟语气的主从句中，如果条件从句中有were，had，should或could，在书面语中可以将连词if省略，将这些词移至主语之前，构成倒装句。 Were you in my place，what would you do about the problem？ Had he come earlier，he would have met her. Should you change your mind，let us know. 6． 混合虚拟语气 在表示虚拟语气的句子中，有时条件从句的动作与主句的动作所发生的时间不一致，这时动词的形式应根据需要加以调整，这种现象称为混合虚拟语气。 If you had taken your medicine yesterday，you would be quite all right now. If I were Mary，I would have bought that dictionary. If we had not got everything ready by now，we should be having a terrible t