高中语法虚拟语气和it用法含习题.docVIP

虚拟语气讲义 I、虚拟语气在条件句中的应用 条件从句和主句中谓语动词形式表 情景 条件从句 主句 与现在事实相反 动词的过去式；be的过去式一般都用were would/could/might/should + do 与过去事实相反 had + 过去分词 would/could/might/should+ have+过去分词 与将来事实相反 should + do; were to do;did(were) would/could/might/should + do 基本用法 （1）与现在事实相反 I would certainly go if I had the time. (The fact is that I have no time.) If he were here, everything would be all right. (He is not here in fact.) （2）与过去事实相反 If I had left a little earlier, I would have caught the train. I would have made a bad mistake if I hadn’t taken your advice. （3）与将来事实相反 If I were to do it, I would do it in a different way. (I will not do it. We wouldn’t lose courage even if we should fail again. 特殊结构的虚拟条件句 （1）If it were not for… If it had not been for… but for… 相当于without 例如：If it were not for your help, I could never go to college. But for the captain, the ship would have sunk with all the passengers on board. If it had not been for the PLA men, his hometown might have been destroyed by the big flood. （2） 假设的情况通过上下文表示出来 I was ill that day. Otherwise I would have taken part in the procession. I would have called on you during my stay in Hongkong, but I didn’t know your address. You were not on the plane, or you would have been killed. Without electricity, there would be no modern industry. （3） 如果条件句中有动词were, had, 或should，可省略if, 把这些动词放在主语前面 Had they time, they would certainly come and help us. (= If they had time, they ….) Should I be free tomorrow, I would come to attend your meeting. (= If I should be free, I ….) Were I in your position, I wouldn’t let him go there. （4） 错综条件句 、混合条件句 在有些虚拟条件句中，虚拟的主句动作与从句动作并不在同一时间发生，这种从句与主句动作发生时间不一致的虚拟条件句称为错综时间条件句或叫混合条件句。这时从句与主句按各自发生的时间构成相应的虚拟式。 If you had followed my advice, you would not be in such trouble now. If he had told me his telephone number yesterday, I would be able to ring him up now. II、 虚拟语气在宾语从句中的应用 在表示建议、要求、命令等动词的宾语从句中，从句中常用 (should) do 形式。 (suggest, require, demand, order, command, request, ask, insist…)例如： I require that he come by te