内 容 提 要
语气是一种动词形式，用以表示说话者的意图或态度。虚拟语气表示说话者的主观愿望、假想和建议等，所说的话有的与现在事实相反，或与过去事实相反，或与将来事实相反或与将来事实可能相反。所以虚拟语气总是与假设条件句用在一起。除了if条件句外，还有几种常用的条件句，短语也可表示条件。此外，上下文也能创造虚拟的语言环境。但有时条件从句与结果主句可能发生时间不一致，有时虚拟语气会出现倒装情况。除了与条件句在一起使用的主句用虚拟语气外，有些宾语从句或表语从句也有用虚拟语气的情况。
I虚拟语气的形式与基本用法
一、虚拟语气的形式
虚拟(条件)语气中，主句与从句中谓语动词的形式可分为下面四类
假设类型
条件从句谓语
动词形式
主语谓语
动词形式
与现在事实相反
动词的过去式(be用were而不用was)
would(第一人称可用should)
+动词原形
与过去事实相反
had+ -ED分词
would(第一人称可用should)
+have + -ED分词
与将来事实相反
were to + 动词原形
would(第一人称可用should)
+动词原形
与将来事实可能相反
should + 动词原形
would(第一人称可用should)
+动词原形
二、虚拟语气的基本用法
1. 与现在的事实相反
1) What type of automobile would you buy ?
[A] if you have free choice to choose the cars available today
[B] if you are free to choose among all the cars available today
[C] if all cars available were free to be chosen by you
[D] if you were free to choose among all the cars available today
2. 与过去的事实相反(有时主句中的should have done表示责备或后悔)
2) ，he would have come to class.
[A] If Mike is able to finish his homework
[B] Would Mike be able to finish his homework
[C] If Mike could finish his homework
[D] If Mike had been able to finish his homework
3) If the United States had not entered the Second World War，probably the 1940 unemployment rate of 14% still further.
[A] would rise
[B] would risen
[C] would have risen
[D] had risen
4) Top?grade [A] diamonds had not [B] increased so sharply [C] in value in the late seventies [D] if one company had not controlled almost all of the world’s supply.
3. 与将来的事实相反
5) The report would be [A] released last January if new developments had not [B] made it necessary to revise all conclusions drawn from [C] the first series of [D] experiments.
6) It is said Tom will go to an appointment tommorrow. If he were to come tomorrow, I ask him to go to your place.
[A] will
[B] would
[C] shall
[D] might
7) If you to see Mary，what would you tell her?
[A] are
[B] will be going
[C] must
[D] were
4. 与将来的事实可能相反
(1) If it should rain tomorrow, I would stay at home. 要是万一 明天下雨，我就呆在家里不出去。 事实上 现在天气很好，明天下雨的可能性应该不大，不过也说不准。
(2) If I should see her next Monday, I would tell her about it. 如果下周一我能见到她的话我就把这件事告诉她。
三、例题解析
1) D为正确答案。
2) D为正确答案。
3) C为正确答案。
4) B错。改为would have not。
5) A错。改为would have been。
6) B为正确答案。
7) D为正确答案。
II 虚拟语气的特殊表现形式
一、表示“好像”：除了if条件从句外，由as if和as though等引导的状语从句表示方式时，意思是“好像”,这时从句中的谓语动词应用虚拟语气。其动词形式用过去时(be用were的形式)表示所说的与现在的事实相反;用过去完成时表示所说的与过去的事实相反
1) Violetta has a curious [A] expression on [B] her face as though she was smiling [C] about something that amused her [D] .
二、特殊连词的需要：lest, for fear that和in case引起的从句(这时谓语多用should+加动词原形)
We dare not play jokes on Mr. Wang lest he should become angry. (我们不敢跟王先生开玩笑，恐怕他生气。)
He hurried on, lest he should drop out in the forced match. (他加紧步伐，生怕在急行军中掉队。)
Every attention must be paid to him lest he (should) feel that he is inferior to my other guests. (我对他特别关照，唯恐他感觉到比我的其他客人低人一等。)
He’s working hard for fear that he should fail in the exam. (他加紧学习唯恐考试不及格。)
