四级考前语法复习new打印.docVIP

虚 拟 语 气He walks as if he was drunk. He walks as if he were drunk. 2）虚拟语气的使用范围 主要用于if条件状语从句。也可用于主语从句、表语从句、宾语从句等。 3） If条件句（后退一步法） 主句 与现在事实相反 1.did 2.were would do 与过去事实相反 had done would have done 与将来事实相反 1.did 2.should do 3.were to do would do 主句：用情态动词would, should, could, might等加一个与从句一致的动词形式。 例：If I had met her yesterday, I would have told him. If I were a teacher, I would be strict with my students. If it should snow tomorrow, they couldn’t go out. 4）If虚拟语气的具体分析： 1. 表示与现在事实相反的假设，其if 从句的用动词的过去式()，主句用would/ should/ could/ might +动词原形。　　1) If places ______ a like, there would be little need for geographers地理学家　　2) If I _____ the meaning of the word, I wouldnt have to look it up.　　2. 表示与过去事实相反的假设，if 从句用过去完成时即had＋过去分词，主句用would / should / could / might + have +过去分词。　　3. 表示对将来实现的可能性很小的或不确定的假设。If从句的谓语形式用一般过去式或用were to / should +动词原形，主句用would / should /could/ might +动词原形　 Jean doesnt want to work right away because she thinks that if she ______ a job she probably wouldnt be able to see her friends very often.　　4. 省略if 采用倒装语序的条件句将had , should, were 等词提到主语之前，即用倒装结构。（这种结构在口语中很少使用）。　　Had he worked harder, he _____ the exams. get through)5）宾语从句中的虚拟语气 一、wish 后面宾语从句中的虚拟语气。按“后退一步法”处理从句的谓语动词。 二、表示“要求、建议、命令”等动词后面的宾语从句中的虚拟语气从句中用“should + 动词原形”构成 三、would rather ＋从句,在这种结构中，从句的位于动词用过去形式表示虚拟。 6）主语从句中的虚拟语气 一、It be + 形容词 + that ．．．（should）．．． 二、It be + 过去分词 + that ．．．（should）．．．． 三、It is time（about time， high time）that ．．．（过去式动词形式或should＋动词原形）．．．． 7）表语从句、同位语从句中的虚拟语气 在suggestion， proposal， order， plan， idea， advice， decision等表语从句、同位语从句中，要使用虚拟语气。其谓语动词应用：should＋原形动词。 8) otherwise We didnt know his telephone number, otherwise we _____ him,　　A) would have telephoned 　　 B) must have telephoned 　　C) would telephone 　　　　　 D) had telephoned 9) but for+名词 要不是 If条件句（后退一步法） 主句 与现在事实相反 But for+n would do 与过去事实相反 But for+n would have done If条件句（后退一步法） 主句 与现在事实相反 if it were not for+n would do 与过去事实相反 if it had not been for+n would have done = if it had not been for…,