高中语言虚拟语气讲解 教案
展开虚拟语气讲解
顾名思义，虚拟语气用来表示说话人的主观愿望或假想，不一定是事实，或与事实相反。语法中为了彰显一句话为虚拟语气，通常使用特殊的谓语动词形式。由此可将虚拟语气划分为四种类型：①退一个时态；②should+动词原形；③if条件句；④其他。
一：退一个时态（简易图解）
所谓动词的“退一个时态”指的是：
⒈假如一句话要表达通常性、规律性、习惯性的状态或者动作，那么其谓语动词使用一般现在时（do）。这种时态下若使用虚拟语气，动词要退一个时态使用过去时(did)。
⒉同理，对一般过去时句子的虚拟也是退一个时态，使用过去完成时。谓语动词由本来的(did)改为had done。
⒊对一般将来时(will do)虚拟时自然就使用过去将来时(would do)。
注意：假如谓语动词是be动词的场合，相应的退成were，had been ，would be。在虚拟语气中，不习惯使用was，而习惯使用were。
符合这一规则的虚拟语气符号分别是：
- Wish 希望
现在时：wish 所跟句子谓语动词用过去时。例如I wish I were you.
过去时：wish 所跟句子谓语用过去完成时。例如I wish I had seen the movie yesterday.
将来时：wish 所跟句子谓语用过去将来时。例I wish I would become a scientist tomorrow.
注意：wish常表示美好的希望，hope后常跟真实的希望。所以hope后不跟虚拟语气。
- As if / as though（好像）
He rushed here breathlessly, as if/as though he had seen a ghost.
他气喘吁吁的跑过来，就好像见了鬼一样：
注意：as if，as though并非必须使用虚拟语气。如果说话人认为事实上就是很像，也可以不虚拟。用还是不用虚拟语气取决于说话人的认识。例如第三册第一单元课文原句：
The country, covered with cherry tree flowers, looks as if it is covered with pink snow.
整个国度到处是盛开的樱花，看上去就像覆盖了一层粉红色的雪。
- would rather, would sooner, would prefer（宁愿做…）；if only… （要是…就好了！）
这些说法常表示与客观事实不相符的一种愿望，故使用虚拟语气。
过去时谓语动词用 had + done： I'd rather you had bought that bag yesterday.
现在时谓语动词用 did： I'd prefer that you came here now.
将来使用would do。注意would rather为特例，其后的虚拟语气用一般过去时did。
例如：We'd rather you did that tomorrow.
If only的例句：
If only I had attended that lecture! The exam was all about it!
要是我听了那堂演讲就好了！考试题目都跟它有关！
二：(should) + 动词原形的虚拟语气
- 表“命令，要求，建议”语义的词，后跟的从句习惯用(should) + 动词原形的虚拟语气。口诀：
一个坚持insist， 两条命令 order，command
三个建议suggest, advice, propose. 四项要求ask, require, request, demand.
例如He suggested that we (should) go to school on time.
注意：此类词还有desire(渴望)，urge(敦促)，recommend(推荐)等。
另外，suggest如作“表明”讲，不虚拟：his pale face suggested that he was ill.
Insist作“坚持说，坚持认为”时不虚拟，只有做“坚持要求”时才虚拟
例如He insists he is a student. / He insists he (should) be sent to America to learn more.
2. 表“以防万一”语义的词和短语：in case, for fear that, least
She examined the door again for fear that / least a thief (should) come in.
她又把门检查了一遍，以防盗贼的进入。（盗贼的进入是可能性很小的一种情况，虚拟）
It’s a fine day. But bring an umbrella along in case it should rain.（in case后保留should）
今天天气不错，但是还是随身带着伞吧，以防万一天会下雨。（可能性很小，虚拟）
3. It is...that…形式主语结构中，it is后如果有特定的形容词 如：necessary、important、natural、strange、impossible、surprising时。
例如: It is necessary that he (should) be sent to prison. 有必要把此人投入监狱。
三：if 条件句。
If条件句是指一种表示假设的主从复合句，一般由连词 if 引导的条件从句引出某种假设，再由主句表示基于这种假设下的反馈。语意一般是 “如果……那么……”。
试分析：If I knew his telephone number, I would tell you.
公式： 对常用时态进行虚拟时，if条件句和主句谓语的使用
| If 条件句 | 主句 |
现在 | did | Should/could/would/might + 动词原形 |
将来 | did，should do，were to do | 上同 |
过去 | had done | Should/could/would/might + have done |
注意Should/could/would/might的选用是根据语义。分别是：应该，能够，就会，有可能。
例：现在：If I had money, I could lend you some. 如果我有钱，就能借你点了。
我现在有钱吗？没有。我能借你点吗？不能。均与现在事实相反，符合现在时虚拟公式。
将来：①．If he should come here tomorrow, I would talk to him.
如果他明天来这儿的话，我就跟他谈谈。
②．If there were a heavy rain next Sunday, we could not go hiking.
如果下周日下大雨，我们就不能去远足了。
③．If she were to be here next Monday, I might tell her about the matter.
如果她下周一来这儿的话，我可能会告诉她这件事的始末。
过去：If he had taken my advice, he would not have made such a mistake.
如果当初他听我的劝告的话，就不会犯这样的错误了。（没听劝，也犯了错误）
对If条件句的公式进行准确记忆非常重要，但考试中则常考其变化体。分别是如下三种条件句：
1. 含蓄——不使用if条件句，代之以without… / but for… / …, otherwise...
例如：But for his help, we would be working now. 要不是他的帮助，我们还会在工作呢。
Without your instruction, I would not have made such great progress.
要是没有你的指导，我不会取得如此大的进步。
We didn't know his telephone number, otherwise we would have telephoned him.
我们不知道他的电话号码，否则我们就会给他打电话。
做对的关键是找准时态，注意这三个短语所引导的结构相当于if条件句，逗号后面跟的是公式中的 主句。做错的情况多是误认为逗号后面是从句。
2. 错综——从句和主句分属不同的时态。例如：假如你当初采纳我的建议，现在就不会处于麻烦之中了。你当初采纳我的建议了吗？没有。现在不处于麻烦之中吗？处于。从句和主句都虚拟，但从句是对过去虚拟，主句是对现在虚拟。各自符合各自的公式。
所以应该这么说：If you had taken my advice, you would not be in trouble now.
3. 倒装——记住下面四组表述，根据实际情况改换代词即可。
If I were you -- were I you， If I should do -- should I do
If I were to do -- were I to do If I had done -- had I done
Should he agree to go there, we would send him there.要是他答应去的话，我们就派他去。
Were she here, she would agree with us.如果她在这儿的话，她会同意我们的。
Had he learnt about computers, we would have hired him to work here.
如果他懂一些电脑知识的话，我们已经聘用他来这里工作了。
四：其他
1. 情态动词+ have done类
①. should have done 表示“过去本应该做某事却未做。”其否定结构 shouldn't have done 表示 “过去本不该做某事却做了。”
eg. You should have worked harder! You failed in 3 subjects this term!
You shouldn't have stolen anything from the store.
②. ought to have done 与should have done同义，其否定结构为 oughtn't to have done。
eg. You ought to have worked harder! You failed in 3 subjects this term!
You oughtn't to have stolen anything from the store.
③. need have done 表示“过去本有必要做某事却未做。”其否定结构 needn't have done 表示 “过去本没必要做某事却做了。”
eg. You need have done your homework before you went out to play.
You needn’t have hurried. Because haste makes waste
④. could have done 表示“过去本能够做某事却未做。”注意：其否定形式 couldn't have done 没有虚拟语气的用法，couldn't have done 只能表推测，相当于 can't have done，意为：“过去不可能做了某事。”
eg. I can't imagine how he could have thought of doing such a thing
He couldn't have done such a stupid thing last night .
⑤. may (might) have done 表示“过去本可以做某事却未做。” 注意：其否定形式 might not have done 没有虚拟语气的用法，might not have done 只能表推测，相当于 may not have done，意为：“过去可能没有做某事。”
eg. Mary may/ might have learned some Chinese before.
He may /might not have received my invitation for he likes party.
2. “是时候做某事了”。
It is (high / about) time that + 主语+ 动词的过去式（偶尔也使用should + do）。
例如It is time that I went to pick up my daughter at school. 我该去学校接我的女儿了。
It is high time you should go to work.你早该上班了。
3. 表特别美好的祝愿。
May you succeed! 祝你成功！ May you be happy! 祝你幸福！
Long live our friendship! 愿我们的友谊天长地久！
God bless you! 愿上帝保佑你！
4. 在so that, in order that所引导的目的状语从句中，从句中的谓语为：can / could / may / might / will / would / should + do。
例如 He goes closer to the speaker so that he can hear him clearer.
他走近说话的人以便能听得更清楚。
He read the letter carefully in order that he would not miss a word.
他把信读得很仔细以便不漏掉一个字。
