课程内容
高中英语《艺术 Unit 1 Art(Part 4)》（选修6）

一、语气的分类
英语的动词一般可带三种不同的语气：陈述语气，祈使语气和虚拟语气。不同的语气用动词的不同形式来表示。
陈述语气
I went to the thearte yeaterday.
Jack hasn't come back home yet.
祈使语气
Let's go.
Don't touch anything on the table until the bell rings.
虚拟语气
If I were you,I would not leave her alone.
Our teacher suggested that we go to the library this afternoon.
(The Subjunctive Mood)表示说话人所说的话不是事实，二十一种假设，愿望，怀疑或推测，虚拟语气主要用于if条件状语从句，也可用于名词性从句等。
条件句表示主句的条件，分真实条件句和虚拟条件句两种。
a 真是条件句表示条件时真的或有可能实现的，采用陈述语气。
b 虚拟条件句 表示条件是无法实现或几乎无法实现的，采用虚拟语气。
二、“if”虚拟条件句的概念
由"if"引导的虚拟条件句叫作“if"虚拟条件句
I could easily recognize if I had seen him before.
其他虚拟条件句
Without your help,I could't have finished my work on time.
三、if Sentence Structure
"if"虚拟条件句的结构
a 表示与现在事实相反的假设
b 表示与过去事实相反的假设
c 表示与将来事实相反的假设
虚拟语气
1.虚拟语气用于条件状语从句中
（1）表示与现在事实相反的假设，条件状语从句中的谓语动词用“过去式（be动词的过去式用were)”,而主句中的谓语动词“would/should/could/might+动词原形”。
If I were a boy,I would join the army.
What would you do if you won the lottery?
If I won the lottery,I would...
If I won the lottery,I would buy an expensive car.
If I had a lot of money I would buy a villa.
If I had a lot of money now,I would travel around the world.
If it were fine now,I would go shopping.
Practice 1:Fill in the blanks
a If they were (be) here,they would take(take)your advice.
b If the world-war burst(burst) out again,what would happen(happen) to our people on earth?
c If the policeman were not(be not)in that room,it could be (be) very dangerous.
d If I were (be)in your position,I would ask(ask) for teacher's help.
2.与过去的事实相反
从句的谓语用had+过去分词，构成If I (we,you,he,they)+had+过去分词的形式；主句的谓语用should(第一人称）/would(第二、三人称）/could/might have+动词过去分词
If he had driven more carefully,he would not have had the car accident yesterday.
Practice 2:Fill in the blanks
a If Tom had been (be)more careful in the exam,he would have passed(pass) it already.
b If you had not (get)up earlier,you would have caught (catch)the first train.
c If I had met(meet) you yeaterday,we would have gone(go) to the concert together.
3.与将来事实相反
从句的谓语用If I (we,you,he,they)+过去分词的形式或were to do或should do形式，主句谓语用should(第一人称）/would(第二、三人称）/could/might +动词原形
假如他来了，我们对他说什么呢？
If he were to come,what should we say to him?
假如他看见我，就会认识我。
If he should see me,he would know me.
Practice 3:Fill in the blanks
a If there should be(be) no natural resource any more,we should make(make)use of nuclear power.
b What would happen(happen) if you should get up (get up)too late tomorrow?
c If Robots were to control(control) the world some day,here would be(be)no friendship.
主句与从句的动作发生在不同的时间，这时主从句谓语动词的虚拟语气形式因时间不同而不同，这叫做混合条件句。
例句中从句与过去事实相反，主句与现在事实相反
If you had asked him yesterday,you would know what to do now.
一、虚拟语气在条件状语从句中的用法
条件从句：现在      If 从句的谓语形式：过去时（were)     主句的谓语形式   would/could/should/might+v.(原）
条件从句：过去      If 从句的谓语形式：过去完成时     主句的谓语形式   would/could/should/might+have+p.p.
条件从句：未来      If 从句的谓语形式：1.过去时  2.should+v.  3.were to do      主句的谓语形式   would/could/should/migh+v.(原）
二、虚拟语气在宾语从句中的用法
1.在动词wish 后的宾语从句中，表示与现在或过去的事实相反、或对将来的主观愿望，从句通常省略连词that
1)表示对现在情况的虚拟：从句动词用过去式或过去进行式（be动词一般用were）。
（2）表示对过去情况的虚拟：从句动词常用'had+过去分词”
（3）表示对将来的主观愿望：从句动词形式为："would+动词原形”
注意：主句的主语与从句的主语不能相同，因为主句的主语所期望的从句动作能否实现，取决于从句主语的态度或意愿（非动物名词除外）
二、在表“建议”“命令”“计划”“要求”等含义的动词的宾语suggest,propose,demand,request,require,order,insist等动词后的宾语从句中，谓语为“(should) do"形式。
例如：
I suggest/propose/demand/request/require/order/ that he(should)be sent to the nearsest hospital as soon as possible.
注意：当suggest 表示“暗示”之意时，则不用虚拟语气；当insist表示“坚持认为”之意时，则也不用虚拟语气。
关于虚拟语气 辨析1
虚拟语气的误用辨析：
1.（误）I shouldn't do that if I was you.
(正） I shouldn't do thst if I were you.
如果我是你，我不会那么做。
表示与现在事实相反的虚拟语气不能用was,只能用were.
关于虚拟语气 辨析2
2.(误）If my father were here now,he will tell me what to do.
(正）If my father were here now,he would tell me what to do.
如果我父亲现在在这儿，他会告诉我怎么做。
表示与现在事实相反的虚拟语气中，主句的助动词只能用would,might 等过去时。
关于虚拟语气 辨析3
3.（误）If I knew her telephone number,I would have called her.
(正）If I had known her telephone number,I would have called her.
如果我知道她的电话，我就给打了。
表示与过去事实相反的虚拟语气中，条件从句的动词要用过去完成时。
关于虚拟语气 辨析4
4.（误）If it had not rained yeaterday,he might come.
(正）If it had not rained yeaterday,he might have come.
如果昨天不下雨，他可能就来了。
表示与过去事实相反的虚拟语气中，主句的动词要用助动词的过去时might 或could+have+过去分词。
关于虚拟语气 辨析5
5.（误）I don't think that I shall fail.But if I fail,I would try again.
(正）I don't think that I shall fail.But if I should fail,I would try again.
我认为我不会失败，但要是我失败了，我会再努力。
表示与未来事实相反的虚拟语气中，条件从句的动词用shold 加动词原形。
Homework
句型练习（用If I were you 句型翻译下下列句子）
1.我要是你的话，我就会把英语学好。
2.如果你昨天来，你就会看见他。
3.万一明天下雨，我们就不到那儿去。
4.我希望我十年前就认识他。
5.他对待我就像对待他自己的儿子一样。