虚拟语气是指所说的话只是一个与事实相反的主观愿望或假想。虚拟语气可用于条件状语从句、名词从句以及其他结构中。if引导的非真实条件中的虚拟语气。
1、三种形式。
具体情况见下表：假设类型 if条件句谓语动词形式主句谓语动词形式与现在事实相反动词用过去时形式（be用were）/would / could / might + do(动词原形) /与过去事实相反 had done
would / could / might h**e done 将来不可能发生。
were to do或should do
would / could / might + do(动词原形)
例：1. if there were no gr**ity, we would not be able to walk on the earth.
假如没有引力，我们就不可能在地球上行走。
2. we would h**e succeeded if we had made enough preparations. 当初要是作了充分的准备，我们就有可能成功。
3. this kind of boiler is very safe. if it were to go wrong, the controlling system would cut off the fuel oil supply automatically.
这种锅炉很安全。万一锅炉发生故障，控制系统会自动切断燃油的供给。
2、if虚拟条件句的省略。
若虚拟条件从句中有were, had, should, 可把if省略，而把were, had, should提到主语前面，成为倒装结构。
例： i were you, i would accept the challenge. →were i you, i would accept the challenge.
2. if you had informed me earlier, i wouldn’t h**e signed the contract.
→had you informed me earlier, i wouldn’t h**e signed the contract.
当初你要早点告诉我，我是不会签那个合同的。
3、错综时间条件句。
在这种虚拟条件句中，从句动作和主举动作发生的时间不一致，因此，从句和主句的谓语动词要根据各自所指的不同时间选择适当的动词形式。
例：1. if i were you, i would h**e taken that job. （从句指现在，主句指过去）
你错过了这么好的机会。我要是你，我当时就接受那份工作。
2. had her husband not been killed in the war, she would not be helping others with housework now. （从句指过去，主句指现在）
如果她的丈夫那时没有死与战争的话，她现在不会帮人做家务了。
4、含蓄虚拟条件句。
有时假设的情况并不以条件从句表示出来，而是以其他形式表现出来。
1）介词短语but for 或 without。译：“要不是，要是没有”。
例：1. but for electricity (=if it were not for electricity), there would be no modern industry.
要是没有电，就不会有现代化工业。
2. without your help (if it had not been for your help), we could not h**e succeeded. 当初没有您的帮助，我们不可能成功。
2）or 或otherwise。句型：did(过去时)，or / otherwise would h**e done.
例：i ran all the way to school, otherwise i would h**e been late. 我一路跑到学校，否则，我就会迟到了。
3）but句型：
（1）would do but do (一般现在时)
（2）would h**e done but did (一般过去时)
my daughter would gain weight but she doesn’t eat enough.
---why didn’t you help him out?
---i would h**e but i didn’t h**e money.
5、wish后的宾语从句和if only引导的感叹句中的虚拟语气。wish后的宾语从句和if only引导的感叹句表达的是与客观事实相反的愿望，需用虚拟语气。
wish that从句 = if only + 从句译：“要是。就好了”或“但愿。
1）愿望与事实相反。从句谓语动词用：were或did (过去时形式)
i wish i knew the answer to the question. =if only i knew the answer to the question. 我要能知道那个问题的答案就好了。
2）愿望与过去事实相反。从句谓语动词用：had done (过去完成时形式)
---we had a great time last night.
---i wish that i had not been ill yesterday. =if only i had not been ill yesterday. 昨天我要是不生病那该多好啊！
3）愿望将来不大可能发生。从句谓语动词用：would / could / might do
i wish that it would be fine tomorrow. =if only it would be fine tomorrow. 但愿明天是个好天气。
6、“(should) +动词原形”的形式在名词从句中的运用。在这些从句中should可以省略，具体运用在以下三种情况下。
1）用在谓语动词为suggest（建议），insist（坚持），adivse（建议），order（命令）， desire（希望），demand（require， request）（要求、请求）的宾语从句中。
2）suggestion, advice（忠告）, order, demand, desire（愿望）等名词后的同位语从句或表语从句中。
3）在固定句型中：
it is important / necessary (essential) (必要的)/ desirable (希望) that (should) do
例：1. i suggest that our manager (should) go there by sea. 我建议我们的经理由海路去那里。
2. our desire is that we (should) get a rise in salary as soon as possible. 我的愿望是能尽快涨工资。
3. it is essential that you (should) win the voter’s hearts. 赢得选民的心是绝对必要的。
2023年高考英语语法复习题
英语 2011高考考前语法加油冲刺解析题 14 1301 the father as well as the mother and their children to make up a trip to beijing.译文 父亲母亲和孩子们都希望到北京去旅行。a.wish b.wishes c.a...
2023年高考英语语法复习题
英语 2011高考考前语法加油冲刺解析题 15 1401 the boy wanted to ride his bike in the street,but his mother told him 译文 小孩想在街上骑自行车，可妈妈不让他骑。a.not do it b.do not to c.not...
2023年高考英语语法复习题
英语 2011高考考前语法加油冲刺解析题 15 1401 the boy wanted to ride his bike in the street,but his mother told him 译文 小孩想在街上骑自行车，可妈妈不让他骑。a.not do it b.do not to c.not...