三、虚拟语气 (The Subjunctive Mood)
表示说的话不是事实，或者是不可能发生的情况，而是 一种愿望、建议或与事实相反的假设等。一般常用于正 式的书面语中。 该语法主要用于if条件状语从句。也可用于主语从句、 表语从句、宾语从句等。 通常有三种情况： ①与过去事实相反。 （过去虚拟） ②与现在事实相反。 （现在虚拟） ③与将来事实可能相反。（将来虚拟） “后退一步法” ①与过去事实相反，在从句中用过 去完成时形式表示。 ②与现在事实相反，用一般过去 时形式表示。 ③与将来事实可能相反，用过去将来时 形式表示。
7. I didn't see your sister at the meeting. If she _____, she would have met my brother. (1994) A. has come B. did come C. came D. had come
9. You didn't let me drive. If we _____ in turn, you _____ so tired. (1996) A. drove; didn't get B. drove; wouldn't get C. were driving; wouldn't get D. had driven; wouldn't have got
1. If she had worked harder, she _____ . (1986)
A. would succeed B. had succeeded C. should succeed D. would have succeeded
3. If my lawyer _____ here last Saturday, he _____me from going. A. had been; would have prevented B. had been; would prevent C. were; would prevent D. were; would have prevented
2.表示与过去事实相反，谓语动词的主要 形式如下
条件从句 had + done 主句 would (might / could /should ) + have done
1) If he had seen you yesterday, he would have asked you about it. 2) If you had come earlier, you would (might) have met him. 3) I would have called you if I had known your phone number.
3.表示与将来事实可能相反，谓语动词的主要形式如下：
条件从句 did should do were to do
主句
Would(could/might/s hould) + do
1) If it should rain, the crops would be saved. 2) If it were to snow tomorrow, they would not go out. 3) If it rained tomorrow, we would not go out.
二、祈使语气 (The Imperative Mood)
用来表示请求、命令或劝告等。 如： 1.Sit down, please. 2.Don't say it in Chinese. Say it in English, please. 3.Let me have a try. 4.Let him go.
Note: 省略连词if。在书面语中，如果虚拟条件句 中有were, had或should，可以if把省略而把 这几个词放到主语之前构成主谓倒装：例如： 1. Should he comeim to ring me up. 2. Were I you (If I were you), I would not do it. 3. Had he been more careful (If he had been more careful), such mistakes could have been avoided.
5. If he ______ , he _____ that food. Luckily he was sent to the hospital immediately. (1993) A. was warned; would not take B. had been warned; would not have taken C. would be warned; had not taken D. would have been warned; had not taken
Subjunctive Mood
虚拟语气
英语动词一般可带有三种不同的语气 (mood)： 陈述语气、祈使语气和虚拟语气。 不同的语气用动词不同的形式 (有的还借助句法形式）来表示。
一、陈述语气 (The Indicative Mood)
用来陈述事实，有肯定、否定、疑问或感叹等形式。如： 1. My father and I drove over to the village to see Mr Wu. 2. People don't hibernate. 3. What a strange-looking person (he is)! 4. Are you joking?
I. 虚拟语气在主从复合句中的用法
1. 表示与现在事实相反，谓语动词的主要形式如下：
条件从句
did（be动词一般用were）
主句
would (should, could, might ) + do
1) If I were you, I shouldn't do that. 2) We would go with you if we had time. 3) We could ask him if he were here. 4) If I knew his telephone number, I would ring him up.