高中英语语法课件_虚拟语气(全)(共55张PPT)详解

解题思路
本题前半句是表示与过去事实相反的虚拟条件 从句，后半句是表示与过去事实相反的主句。 相当于：If he had worked harder, he would have got through the exams.本题的 答案是B. would have got through。 选项A. must have got through（肯定通过） 表示一种对过去事情的主观推测，不是与过去 事情相反的情况。另外，must不能用在虚拟条 件句中。 选项C. 和D. would / could get through （就会通过）是虚拟语气现在时的一种表示方 法，表示与现在事实相反。
为什么要学习虚拟语气？
虚拟语气是四级考试中重点考察的语法 点。历年四级考试中，仅仅单项填空部
分就一共出现了48道虚拟语气的题 目！！！
II. 虚拟语气的最基本形式
非真实性条件句是虚拟语气最基本的表 现形式。
i. 由“if” 来引导的非真实条件句
组成方式： 非真实的条件从句 + 假设结果（主句）
最基本形式的表达方式
语法要点
虚拟语气 Subjunctive Mood
I.什么是语气？
语气是动词的一种形式，用以表示说话 人对某种言行或某种事情的看法或态度。 英语有三种语气：陈述语气，祈使语气 和虚拟语气。 陈述语气一般用来讲述事实或提出疑问。 常常用于陈述句、疑问句和感叹句。 e.g. I took a shower after supper. What are you going to do? What a beautiful flower!
A case in Point
P. 37 (l. 28) in College English II. Unit 3 Were it left to me to decide whether we should have a government without newspapers or newspapers without a government, I should not hesitate a moment to prefer the latter. = If it were left to me to decide…
解题思路
本题是与过去时相反的虚拟句，从句中 用过去完成式，主句中用would have done。 本句相当于If we had known his telephone number，we would have telephoned him。 答案是A) would have telephoned。
实战练习 1
例：1995年6月四级第46题 We didn't know his telephone number, otherwise we _____ him, A) would have telephoned B) must have telephoned C) would telephone D) had telephoned
More examples
要是昨天不下雪的话，我们现在就应该在去 上海的路上了。 If it had not snowed yesterday, we would be on the way to Shanghai. 要是昨天晚上医生来晚了的话，他今天就没 命了。 If the doctor had not come sooner last night, he would be dead today.
ii. 错综时间条件句
有时虚拟条件从句表示的动作和主句发生的动 作在时间上不一致。例如，一个与过去事实相 反，另一个与现在事实相反。这种句子可称为 错综时间条件句。 这时，谓语动词的形式要根据各自表示的时间 来调整。 e.g. If he were alive now, he might have finished his scientific researches on the bridge building three years ago. 如果他现在还活着，他可能三年前就完成了他 的桥梁建筑科研工作了。
实战练习 3
1999年一月四级题： If I hadn’t stood under the ladder to catch you when you fell, you now. A. wouldn’t be smiling B. won’t smile C. couldn’t have smiled D. didn’t smile
iiii.含蓄虚拟条件句
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，仔细一分析就会 发现句子中隐含着一个条件，这种句子称为含 蓄条件句 含蓄的条件可以用下列方式来表达： （1）介词或介词短语 常见的有：but for（要不是）, with, without, in that position（在那个位置）, in the absence of（没有）, under, in, for the fear of…
e.g. But for your help, we couldn't have succeeded in the experiment. = If it had not been for your help, … 如果没有你的帮助，我们的实验不会成功。 没有空气就不会有风和雨 Without air, there would be no wind or rain. = If there were no air, … 如果条件更好一些，我们会做得更好。 Under a better condition, we would have done much better.
(2) 连接词
常见的可以用来引导虚拟语气的连接词 有:and, but, but that, or, or else, other, otherwise(否则)等。 e.g. I’m really busy; otherwise, I would certainly go with you. =if I weren't so busy…
解题思路
这是一道错综时间虚拟条件句。 在本句中，从句是对过去发生的事情进 行假设，主句是对现在情况的假设。 译文：当你掉下来时，如果不是我在梯 子下面把你接住，恐怕你现在就不会笑 了。选A
实战练习 2
If you had taken your medicine yesterday, you ___ well now. A. are B. had been C. would be D. were 正确答案: C
要不是由于交通事故，我就不会上课迟 到了。（我本来上课不会迟到的，可是 发生了交通事故）。 I would not have been late for class but there was a terrible traffic accident. 我本来可以写信给你的，可我没有时间。 I would have written to you, but there was no time. = If there had been time, I would have written to you.
注意！！！
如果条件从句是否定式，倒装时只能把 not 放在主语之后，不能用缩写式把not 放在主语之前。 e.g. Had you not told me about the matter, I should never have known the whole thing. (不能说：Hadn’t you told me…)
祈使语气主要用于祈使句。 e.g. Get out of here! 虚拟语气
II. 什么是虚拟语气？
虚拟语气是一种特殊的动词形式，表示说话人 所说的话不是事实，而是想象、假设、建议、 打算、意见、愿望、怀疑、推测、喜悦等等。 e.g. If we had met her last night, we would have told her what had happened. 如果我们昨晚见到她，我们就会告诉她发生了 什么事。 （实际上，我们并没有见到她，也没有告诉她 所发生的事。）
注意
在主句中，should一般只与第一人称搭 配，could和might各人称都可以使用， 但would是最普遍，最常见的。
Examples
如果他在这里，他就会帮助我们。 If he were here, he would help us. 如果昨天没下雨，我们就去踢足球了。 If it had not rained yesterday, we would have played football. 如果敌人胆敢袭击我们，我们将把他们 全消灭。 If the enemy were to (should) attack us,we would wipe them out completely.
实战练习 2
例：1996年1月四级第44题 Jean doesn't want to work right away because she thinks that if she ______ a job she probably wouldn't be able to see her friends very often. A. has to get B. had got C. were to get D. could have got
实战练习 4
例：1997年6月四级第42题： Had he worked harder, he _____ the exams. A. must have got through B. would have got through C. would get through D. could get through
实战练习 5
2001年1月大学英语四级题目： Some women a good salary in a job instead of staying home, but they decided not to work for the sake of the family. A. must make B. should have made C. would make D. could have made