规则特殊清一色虚拟语气轻松学.doc

规则特殊清一色，虚拟语气轻松学
虚拟语气是高中英语语法学习的一大难点，也是历年高考的重点之一。笔者将其常见用法归纳成七个字“规则特殊清一色”，以帮助同学们愉快学习，轻松掌握。
一、规则
在if引导的非真实条件句中，主从句的谓语动词形式的构成是规则，要牢记。
1、表示与现在相反的情况：条件从句用一般过去时（be 动词一般用were），主句用would/could/might/should+动词原形。例如：
Sorry, I am too busy now. If I ______ (have) time, I would certainly go for an outing with you.
【答案】had。 根据I am too busy now可知是与现在事实相反的虚拟，所以条件从句用一般过去时。
2、表示与过去相反的情况：条件从句用过去完成时，主句用would/could/might/should have+动词-ed形式。例如：
If Mr. Dewey _____(be) present, he would have offered any possible assistance to the people there.
【答案】had had。根据主句中的would have offered可知是对过去事情的虚拟，条件从句用过去完成时。
3、表示与将来不大可能实现的情况：条件从句用一般过去时（be 动词一般用were）或were to + 动词原形或should +动词原形，主句用would/could/might/should+动词原形。例如：
Grace doesn’t want to move to New York because she thinks if she ____(live) there, she wouldn’t be able to see her parents very often.
【答案】。were to live/ should live/lived。句意：Grace不想搬到纽约，因为她认为如果住在那里，她将不能见到父母。根据句意可知是与将来事实相反的虚拟。
热点：虚拟语气在if条件句中的运用是高频考点，考生一定要准确把握从句中的动词形式。
二、 特殊
1、在if引导的非真实条件句中，有下列特殊情况：
⑴ 混合条件：有时条件从句和主句的谓语动词的动作发生的时间不一致，这时动词的形式根据它所表示的时间加以调整。例如：
—The weather has been very hot and dry.
—Yes. If it had rained even a drop, things ______(be) much better now!
【答案】would be 。句意：要是当时下雨了，现在的情况就好的多了！ 从句动作指过去，主句动作指现在。
⑵ 含蓄条件：是指非真实条件句中的条件句有时不表达出来，只暗含在上下文中，常用介词without, but for, 或连词 otherwise, or , or else ,but等暗示。例如：
1) I_______ (go) through that bitter period without your generous help.
【答案】couldn’t have gone。句意：没有你的慷慨帮忙，我不可能熬过那段痛苦的日子。由 without your generous help可知，此处表示与过去相反的虚拟语气。
2) We ____ (put) John’s name on the race list yesterday but for his recent injury.
【答案】would have put。句意：要不是约翰最近受伤了，我们昨天就把他的名字填在比赛名单里了。根据句中的yesterday和 but for可知，此处表示与过去事实相反虚拟语气。
3) We lost our way in that small village, otherwise we ____ (visit) more places of interest yesterday.
【答案】would have visited。句意：在那个小村庄我们迷路了，否则昨天我们会参观更多的名胜。句中的otherwise隐含条件句If we hadn’t lost our way。
热点：含蓄条件也是高频考点，我们要重点掌握。另外 but之前的句子往往是虚拟，but 之后的句子常常是事实。再如：
We ______ (face) the difficulty together, but why didn’t you tell me?
【答案】could have faced 。句意：“我们本来能够一起共同面对困难，但是你为什么不告诉我呢？”。but之后的事情（告诉我是发生在过去的事实，but之前的事情（面对困难）是与过去事实相反的虚拟。
⑶ 省略倒装：当if条件句中有were, should 及助动词had时， 可以省略if，把were, should 及had提前，变为倒装句式。例如：
Had he caught the morning train, he_________ (not be) late for the meeting.
【答案】would not have been。Had he caught…为If he had caught…的省略和倒装，表示与过去相反的情况。
2、wish等动词或短语引导的句子中
有四个动词或短语wish, would rather , as if 引导的从句或 if only引导的感叹句中，谓语动词形式：表示的动作指现在的情况，动词用一般过去时（be 动词一般用were）；表示的动作指过去的情况，动词用过去完成时；表示的动作指将来的情况，动词用一般将来时。例如：
George is going to talk about the geography of his country, but I’d rather he ——_______ (focus) more on its culture.
【答案】focused。句意：乔治打算谈论他的国家的地理，但我宁愿他更多的把焦点集中在文化上。would rather后应用虚拟语气，而此处“把焦点集中在文化上”是指现在的情况，所以用focused。
Don’t handle the vase as if it______ (be) made of steel.
【答案】were。句意：不要拿着这个花瓶好像它是由钢铁制成的那样。根据句意， as if从句是表示与现在相反的虚拟语气，所以动词用一般过去时（be 动词一般用were）。
3、固定句型：It’s (high/about) that…，从句中动词用过去式或should do形式，但should 不能省略。
Jack is a great talker. It’s high time that he ______ (do) something instead of just talking.
【答案】did/ should do。句意：杰克副词善谈，他是该做点实事，而不再只是空谈了。
三、清一色
在表示建议、请求、命令的动词或名词后的从句中以及important, necessary, strange，natural等形容词后的从句中，谓语动词一律should do形式， should可以省略。
Teachers recommend parents _______ (not allow) their children under 12 to ride bicycles to school for safety.
【答案】 not allow/ should not allow。recommend表示“建议”时，其后的宾语从句动词用should do形式，should可以省略。
实战演练：用括号内所给动词的适当形式填空，必要时用上适当的情态动词。
1. ______(be) there no modern telecommunications, we would have to wait for weeks to get news from around the world.
2. If my car _____(be) more reliable, I would have driven to Lhasa instead of flying last summer.
3. I ______(come) sooner but I didn’t know that they were waiting for me.
4. Maybe if I (study) science, and not literature then, I would be able to give you more help.
5. Had I known about this computer program a huge amount of time and energy_____ (save).
6. But for their help，we ( not finish) the program in time.
7. The doctor recommended that you ______( not swim) after eating a large meal.
8. This printer is of good quality. ______ it _____ (break) down within the first year, we would repair it at our expense.
9. Look at the trouble I am in! If only I _____ (follow) your advice.
10. —Where are the children? The dinner’s going to be completely ruined.
—I wish they ( not be)always late.
(Keys: 1. Were 2. had been 3. would have come 4. had studied 5. would have been saved 6. could not have finished 7. should not swim / not swim 8. Should ; break/ Were; to break 9. had followed 10. weren’t )