M6U4虚拟语气讲解 2011.12.16一、虚拟条件句1．非真实条件句的形式，根据时间的不同可分为如下三种：⑴表示与将来的事实或愿望相反①If it snowed / should snow / were to snow tomorrow, we would change our plan．要是明天下雪的话，我们就改变计划。

②If we changed / should change / were to change our plan, they would be disappointed．如果我们改变计划，他们会失望的。

⑵表示与现在的事实或愿望相反(be动词常用were)①If I knew the answer, I would tell you．如果我知道答案，我会告诉你。

②If 1 were rich，I would donate money to the Hope Project．要是我富有的话，我会捐款给希望工程。

⑶表示与过去的事实或愿望相反If you had arrived ten minutes earlier, you could have danced with the American Indians．如果你早十分钟来的话，你就可以和印第安人跳舞了。

2．可以省去条件句中的if，使用倒装句，即把从句中的should，were和had置于句首。

①Should it snow tomorrow, we would put off our celebration．如果明天下雪，我们就推迟庆祝会。

②Were I rich, I would buy an expensive cal．要是我有钱，我就买一辆昂贵的汽车。

③Had you attended the lecture, you could have known the special custom．如果你听了讲座，你就会知道这种特殊的习俗了。

3．虚拟条件句中的谓语可用进行时，表示“如果……正在……”等含义，主句中的谓语仍用would（或might，should，could），并根据情况选用时态。

如：① If we weren’t living in the 21st century, people would treat the event in an old way.要不是生活21世纪，人们会用旧有的方式对待这个事件。

②If Mary were living a hard life, her parents should be responsible for it.要是玛丽生活艰难的话，她的父母应该对此负责。

4．错综虚拟语气(也叫混合时间虚拟语气)如果虚拟句的主、从句中动词表达不同的虚拟动作时间，则该句被称为“混合条件虚拟句”。

句中动词采用何种形式（现在或过去虚拟式）要依据主、从句中的时间状语（或上下文）来确定。

如：①If you worked hard now, you would get a good job in the future．如果你现在努力，将来会有好工作。

②If he had not been caught in the rain yesterday, he wouldn’t be ill now．要是他昨天不淋雨的话，现在就不会生病了。

③If David had received six more votes in the last election, he would be our chairman now．如果大卫在上次的选举中多赢得六张选票，那么他就会是我们的现任主席。

【注意】在混合条件虚拟句中，要注意事实和虚拟假设的混合。

要根据所述事实发生的时间确定它的时态形式。

①I would have gone to visit him in the hospital had it been at all possible，but I Was fullyoccupied the whole of last week．如有可能，我本来会到医院去看望他的，但整个上周我实在是太忙了。

（说明过去情况，用一般过去时）② If Tom didn’t work overtime today, he would come to our reception. However, he is preparingthe coming exam now. 如果Tom今天不加班，他回来我们的宴会的。

然而，他现在正准备即将到来的考试。

（说明现在情况，用现在进行时）③Should it not rain tomorrow, I might travel around our town. What a pity! I will have to helpmy father on the farm. 万一明天不下雨，我可能会周游我们镇。

真遗憾，我不得不在农场上帮助我父亲。

（说明将来情况，用一般将来时）5．“could have + 过去分词”也可用于虚拟条件句中，这时的could是情态动词，表示“能够”，相当于：had been able to……。

比如：① If I could have earned enough money, I should have traveled over the world.要是我挣的钱足够多的话，我就会周游世界了。

② If you could have prevented mistakes, you might have been more successful.如果你能避免错误的话，你会更加成功的。

6．Were it not for sth: （与现在或将来情况相反）要不是因为……Had it not been for sth: (与过去情况相反) 要不是因为……① Were it not for the heavy traffic today, I would set off to my school.要不是因为今天繁忙的交通，我就动身去学校了。

② Had it not for the delay, they could have completed their long march yesterday.要不是因为耽误，他们昨天就能结束他们的长征。

7．隐含条件虚拟句虚拟句中没有明显的虚拟条件，而是利用其他手段来暗示所存在的虚拟条件(可转化为if 条件虚拟句)，此类虚拟句被称为“隐含条件虚拟句”。

⑴由without，but for，with（要不是因为）等词引导的介词短语表示隐含条件。

①I couldn’t have lived through Christmas without giving you a present．(=I couldn’t have livedthrough Christmas if I hadn’t given you a present.) 若不送给你礼物，我无法过这圣诞节。

②But for your timely help，we couldn’t have finished the work on time. (=We couldn’t havefinished the work on time if you hadn’t given us your timely help.)要不是你们及时给予帮助，我们不可能按时完成工作。

③ With better equipment, we could have done it better. 如有更好的设备，我们能做得更好。

⑵ 含有otherwise(副词)，or ，but that(要不是) 等词的隐含条件虚拟句。

① He reminded me of what I should otherwise have forgotten. (=If I had not been reminded ，Ishould have forgotten all about that.) 他提醒了我，要不然我就会把这件事给忘了。

② But that it snowed heavily, they could have arrived there earlier. =But for the heavy snow, they could have arrived there earlier. 要不是大雪，他们本来能到的更早。

⑶ 用不定式表示隐含条件。

① To go there by train would have saved us a lot of trouble. (=If we had gone there by train ，itwould have saved us a lot of trouble.) 要是乘火车去那儿会省去我们诸多麻烦。

② To have studied harder, you would have passed the exam. (=If you had studied harder, youwould have passed the exam.) 如果你学习更加刻苦，你本来会通过考试的。

③ A man would be blind not to see that difficulty. (=If he didn ’t see the that difficulty, a manwould be blind.) 连那个困难都看不见的人一定是瞎了眼。

⑷ 通过句子间的联系或上下文来表示隐含条件。

Einstein care little for money ，though he could have been very rich. (=If Einstein had cared formoney, he could have been very rich.) 尽管爱因斯坦本可以成为非常富有的人，但是他对金钱却不感兴趣。

二、虚拟语气在某些从句中的运用1．由even if (即使、虽然)，as if / though ，if only(但愿、要是……就好了) 引导的虚拟句：与现在情况相反，从句用过去时。

+ 从句 与过去情况相反，从句用had done 。

与将来情况相反，从句用would / could / should / might + do① Even if he had been tended without delay ，no one could have saved him.即使他及时得到护理，也救不活。

② He looks as if he hadn ’t had a meal for a month ．他看上去好像一个月没吃饭一样。