[10-20 18:10:12] 来源：http://www.67xuexi.com 高二英语 阅读：85393次
虚拟语气在 在同位语从句中
同位语从句的先行词常是表示说话人愿望、 建议、要求、命令等的名词。 The suggestion that students (should) learn something practical is worth considering. Do you know the order that you (should) keep watch.
虚拟语气在 在主语从句中
在句型 “It is important (necessary, strange, natural) that .... ” 中，that 后面的从句中的谓语 动词用： should + 动词原形 [ [例句] ] 1. It’s necessary that we should have a walk now. 我们有必要出去散散步。
2. It’s natural that she should do so. 她这样做是很自然的。 3. It’s important that we should take good care of the patient. 重要的是我们要照顾好病人。
虚拟语气在 在 as if 从句中
在as if /though从句中，常用虚拟形式，即表示与现 在事实相反，用过去式；与过去事实相反用过去 完成式 (had done).
一、as if 连接表语从句 She looked as if she were made of ice. 她看起来似乎是冰做的 He looked as if he hadn’t slept for two days.
二、as if 连接方式状语从 句 She looked after the boy as if he were her own son. 她照顾这男孩就像自己的儿子一样。
He speaks to us as if he had been there. 他给我们讲的好象他去过那儿。
虚拟语气中的几个特例
1. if only 意为：若是...那该多好啊; 真希望...; 只要, 只要...就好 表示现在的情况,应用过去式; 如果是过去的情况, 应用过去完成时态 If only I had arrived in time! If only she didn’t drive so fast.
2. It’s (high/right) time that… that 从句要用虚拟语气：谓语用过去时或should + do It’s time that you left/should leave here.
3. 一些介词短语, 如:but for(要不是), without, otherwise(否则), 等表示含蓄的条件,这时主 句要用虚拟语气 Without your help, we would not have made such rapid progress. But for my brother's help, I would not have finished it on time. I had to do sth.more important,otherwise I might have helped.
简单的归纳
1、表示说话人的要求、建议、命令时，常用 (should) do表示虚拟形式, 主要用于名词性 从句中。
2、其它情况常用两种形式：表示与现在事实 相反，用过去式；表示与过去事实相反用 过去完成式。
Exercises
1. Alan ___ the party if he had gone to London. A. would have missed B. had missed C. would miss D. missed
2.—It was the drug，not the disease，that killed the boy. —He would be still alive today if he ________ that drug. A.not take B.shouldn’t have taken C.didn’t take D.hadn’t taken
3. If only I ___ to my parents! (But I didn’t.) A. listened B. had listened C. should listen D. would listen
4. Tom suggested that Ann ___ the house. A. sell B. sold C. shall sell D. would sell
5. I wish this bus ___ to the university. A. go B. went C. has gone D. had gone
6. Simon looks as though he never ___ a square meal(吃得饱), though his parents feed him very well. A. get B. getting C. got D. should get
7. He is talking so much about America as if he ___ there. A. had been B. were C. was D. been
8. I ___ you some money, but I hadn’t got any then. A. would lend B. would have lent C. could lend D. may have lent
9. – Have you ever been to Beijing? -- No, but I wish I ___. A. have B. will C. do D. had
10. I don’t think it is the right time that you __. A. will go B. went C. go D. must go
11. When a pencil is partly in a glass of water, it looks as if it ＿＿＿＿. A. breaks B. has broken C. were broken D. had been broken
12.(2003上海春季高考题)Look at the trouble I am in! If only I ________ your advice. A.followed B.would follow C.had followed D.should follow
13.(2002上海高考题)It is hard for me to imagine what I would be doing today if I ________ in love， at the age of seven，with the Melinda Cox Library in my hometown. A.wouldn’t have fallen B.had not fallen C.should fall D.were to fall
14.She insisted that she ________ ill of him behind him，but he didn’t believe it. A.hadn’t spoken B.shouldn’t speak C.wouldn’t speak D.not speak
15.It is high time the child ________ to the hospital. A.is sent B.would be sent C.be sent D.were sent
16.If it ________ so hard，we’d go to town. A.isn’t raining B.weren’t raining C.doesn’t rain D.has rain
17.It’s strange that he ________ without saying good-bye to us. A.should have gone out B.went C.should go out D.goes out
18.Had you listened to the doctor ， you ________ all right now. A.are B.were C.would be D.would have been
19.I’d rather you ________ know the secret. A.didn’t B.hadn’t C.not D.not to
20.Without your help，we ________ this task. A.don’t finish B.will not finish C.didn’t finish D.would not have finished
21.Isn’t it about time that you ________ to pick up the visitors from New York? A.went B.would go C.go D.will go