1、College English Grammar,Lecture One 虚拟语气,本讲要点 虚拟语气是英语中一个非常重要的语法项目。然而什么是虚拟语气？虚拟语气表达的都是非真实性的条件状语从句吗？其最基本的构成形式是什么？有那些词可以用来引导虚拟语气？ 虚拟语气有哪些特殊的表达形式？如何来辨别和使用这些特殊形式？,一、什么是虚拟语气？,语气是动词的一种形式，用来表示讲话某件 事情的看法或态度。英语中有三种语气：,语气,陈述语气 (Indicative Mood),祈使语气 (Imperative Mood),虚拟语气 ( subjunctive Mood),1,2,陈述语气一般用来讲述事实或提
2、出疑问，常常用于陈述句、疑问句和感叹句。, I took a shower after supper. What does this sentence try to tell us?,祈使语气主要用于祈使句，由说话者向对方下达命令、提出要求、劝告等。, Try your best next time! Let the girl stay away from the fire!,3,虚拟语气是一种特殊的动词形式，用于表示说话人所说的话不是事实，而是想像、假设建议、打算、愿望等。,1. If we had met her last night, we would have told her wha
3、t had happened. 2. If I were you, I would leave the city quickly.,虚拟语气最常见的表达形式就是采用“if”引导的非真实性条件状语从句，主句以及从句明显同过去、现在或将来已经发生的事或将要发生的事实相反。,二、虚拟语气的最基本形式,由于整个句子所表达的是虚拟的概念，因此动词要采用虚拟的表达形式。按照时间的概念不同（过去、现在、将来）可分为3种表达形式：,（一）与现在事实相反的非真实性条件句,If she were here, she would help you. I think if you knew all the circu
4、mstance, you would forgive me.,( 二）与过去事实相反的条件句,The chair would not have been broken if you had been more careful. If my mother had been here last Saturday, he would have prevented me from going.,（三）虚拟语气的将来时,If you succeeded, everything would be all right. If you should succeed, everything would be a
5、ll right. If you were to succeed, everything would be all right.,(四）错综时间条件句,有时候，主句与从句的动作发生在不同的时间，这时主，从句谓语动词的虚拟语气形式因时间不同而不同，这叫做错综时间条件句或混合条件句。,If you had asked him yesterday, you would know what to do now. （从句与过去事实相反，主句与现在事实相反。） If it had rained last night (过去), it would be very cold today (现在).,（五）虚拟
6、语气的倒装省略“if”的条件句,虚拟条件句的从句部分如果含有were, should, 或had, 可将if省略，再把were, should或had 移到从句句首，实行倒装。,Were they here now, they could help us.,If they were here now, they could help us.,Had you come earlier, you would have met him.,If you had come earlier, you would have met him.,If it were not for their help, we
7、 would be in great trouble.,Were it not for their help, we would be in great trouble.,在虚拟语气的从句中，动词“be”的过去时形式一律用“were”，不用was， 即在从句中be用were代替。,注意,(六) 含蓄条件句,在虚拟语气中，有的句子可能没有明显的由“if”引导的条件从句，但是句子中隐含着一个条件，这种句子称为含蓄条件句，通常有以下两种来表达。,1,介词或介词短语。常见的可以引导虚拟语气的介词有：with, without, in the absence of under, but for, for
8、 the fear of等。,In the absence of sunlight, there would be no moonlight. Under a better condition, we would have done much better.,2,连接词。常见的用来连接虚拟语气的连接词 有：and， but，but that，or，otherwise等,Tell me the truth, and you wouldnt have to fear.,But that I saw it with my eyes, I could not have believed it.,即学即
9、用,将上述由介词以及连词引导的虚拟语气句改为相应的由“if”引导的条件句.,三、虚拟语气的特殊形式,虚拟语气的特殊形式是这一语法项目的难点也是国家级考试中的频率较高的考点，其表现形式我们从以下十个方面进行学习记忆。,1,一些动词在接宾语从句时，要用虚拟语气,这些动词有：,suggest, command, propose, recommend, demand, insist, request, etc.,上述动词所接的虚拟语气基本句型是：主句依据说话者要求，采用正常的陈述句相对应的时态，从句用 “should” + “动词原形”，常常省略“should”。,1. Mother insists
10、that the wallet I picked up in the street ( should) be given back to the owner.,2.He intended that she do it right now.,特别提示,这种句式的否定形式，特别是在省略“should”的情况下，“not”否定在从句部分。,2,当上述动词以过去分词形式用在如下句型中时，从句用“should”（可省略）“ V”该句型为：it is/was (上述动词）过去分词that 从句,1.It is strongly recommended that students should listen
11、 to the English news broadcasting in the morning.,2.It was suggested that every scientist master at least one foreign language.,3,当上述动词以名词形式出现，并且被用来做主语引导一个表语从句时，从句要用虚拟语气，其形式同上。,My suggestion was that we ( should ) leave the burning building at once,4,当上述动词的名词形式接同位语从句时，同位语从句用虚拟语气，用法同上。,The students p
12、ut forward the demand that the class ( should ) be started at 8:30 in stead of 8:00.,5,在“it is/wasadvisable, preferable等形容词that 从句”的句型中用虚拟语气。,常见的形容词有：,necessary，important， essential， urgent，vital， natural ，strange， imperative,1. It is vital that he (should) be warned before he takes action. 2. It wa
13、s strange that she (should) have gone away without saying good-bye.,6,在“到了该做的时候了”（It is time that)句型中，从句动词用过去式这种虚拟 形式(有时也可用should+动词原形)。,1. It is time (that) we went to bed. 2.It is high/about time (that) we handed in the homework.,7,在“would rather + that（常省略）从句”的句型中，从句用虚拟语气。从句时态根据句子要表达的意义而定。,Mary w
14、ould rather she had not broken the window.,8,由if only, as if, as though, even if 等引导的从句，要用虚拟语气。,1. He behaves as if he were the owner of the house. 2. Even if it had been a rainy day, I would have gone to see her.,9,在表达愿望的独立句中使用虚拟语气。,1. God bless you! 2. Long live my motherland! 3. So be it then. 4. May you succeed!,The End,
