英语动词有三种语 气， 陈述语气，祈使 语气和虚拟语气（见 课本P 170页）。
定义：用来表示说 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，假 设的语气叫虚拟语气。
条件从句 If 从句的谓语形式 主句的谓语形式
Would/could/should/ 过去时（were） might +V.（原）
过去 过去完成时 might+have+p.p.
1.过去时 2.should+V. 3. were to do
would/could/ should/might +V （原）
1.If I had HIV, I would know because I would feel sick. 2.If I were you, I would give AIDS patient a hug. 与现在事实相反 3. If I had taken your advice, I wouldn’t have made a mistake. 4. If he had been there, it wouldn’t
5.If it should rain tomorrow, they wouldn’t go for an outing. 6.I think we could do it, if we planed it properly and could borrow the tools.
7. If we were to have three days off , we would enjoy a very happy life.
二：虚拟语气特殊句型： 1.Wish 现在： 过去时（were） 的宾语 过去： 过去完成时 从句 未来： would/could/might+V.
1.I wish I were a bird.（现在） 2.I wish I hadn’t made such a mistake. （过去） 3.We wish our parents wouldn’t punish us. （将来）
2. Would rather that
过去： 过去完成时 未来： 过去时
I would rather you paid me now. I would rather you had gone, too. Don’t come. I would rather you came tomorrow.
3. as if /though + Clause
过去：过去完成时 She loves the baby as if it were her own son. It seems that it were spring. I remember the whole thing as if it had happened yesterday.
They talked as if they had been friends for years. He looks as if he were drunk.
过去时 4.It’s (about/high) time +that --should +V.
It’s high time that you went. 你该走了。
It’s high time that you should go.
我们该去 It’s time that we went to bed.
睡觉了。 It’s time that we should go to bed.
宾语从句。常见动词： 一个坚持，两 个命令，三个建议，四个要求。即 1.insist 2. order, command
3. advise, suggest, propose
4. demand , require, request, desire
从句中的动词 使用should + 动词原 形，或者将should省略。
1.We suggested that Tom have a rest. 2.He insisted that I (should )be present. 3.The king ordered that the prisoners be killed the next day. 4.They requested that we (should) send them to work there.
以上动词相应的名词构成的名词性 从句包括主语从句，表语从句和同位 语也要使用虚拟语气。从句中的动词 形式一样。
order, advice, sug
gestion, proposal, demand, request, desire
It’s suggested that the plan be carried out. (主语从句) My demand is that she should come to see me once a week.(表语从句) All of us are for the advice that the chemical factory should be closed down.(同位语从句)
6.without和but for 构成虚拟,but for要不 是 Without sunlight, people’s life would be different from today.
But for your help, I wouldn’t have finished the work.
Without your help, I would have failed.
But for water, it would be impossible to live in the desert.
7. If only …要是就好了
If only I knew his name! If only we had followed your advice!
If only I could see him again!
If only our parents could live with us! If only I hadn’t missed the train!
8. It’s necessary /strange/ natural/ important
+ that---Clause 从句中的动词要用虚拟， 即（should）+动词原形
It is important that we ( should ) master a foreign language. It is strange that she refuse to come to the party. It’s necessary that we should study hard.
Heaven help him!
God bless you! May you succeed!
Long live the People’s Republic of China!
1.假设条件从句谓语动词发生的时间与主句 所假设的谓语动词不一致，叫做错综条件 虚拟语气。主句和从句的谓语动词要依照 假设的时间而顶。
If the weather had been finer, the crops would be growing still better. If you had followed the teacher’s advice, you wouldn’t be in the hospital.
2.假设条件虚拟倒装。 条件从句中有should， were， had三个助动词可以把if省略，并 将这三个词提至句首。
If I were you, I would give it up. Were I you, I would give it up.
If it were not for your advice, we couldn’t have got over the difficulties.
Were it not for your advice, we couldn’t have got
over the difficulties.
If I had had time, I would have run round that lake again. Had I had time, I would have run round that lake again. If there should be a flood, what should we do? Should there be a flood, what should we do?