现将虚拟语气在条件句中的各种具体形式和用法分述如下：1、对现在的虚拟,表示与现在事实相反的假设时,条件状语从句的谓语动词用过去式（be的过去式用were.而主句中的谓语动词用would (should, could, might) + 动词原形.见下表：条件状语从句的动词形式主句的动词形式If+主语+动词过去式(be的过去式were.在口语等非正式场合中,I,he,she,it等后面也可用was.但在If I were you中,一定要用were,不能用was.I (we)should+动词原形主语+would (might,could)十动词原形1、例句：If I were you, I should study English. (fact: I am not you, so I shall not study English.)If he had time, he would attend the meeting.(fact: He does not have time, so he will not attend the meeting.)If they didn’t take physical exercises every day, they wouldn’t be so healthy. (fact: They take physical exercises every day, so they are very healthy.)If you went to bed earlier, you would not be so sleepy in the morning. (fact: You often go to bed late, so you are always sleepy in the morning.)If this were the case, it would be very awkward.(fact: This is not the case, so it is not awkward.) Now let’s do some translation: 要是没有虚拟语气,英语就会容易多了.If there were no subjunctive mood, English would be much easier. 如果我是你,我就在房屋周围种些树.If I were you, I would (should) plant some trees around the house.如果我把头发染成蓝色,人人都会笑话我.If I dyed my hair blue, everybody would laugh at me. Or: I would (should) be laughed at by everybody. 要不是她这么忙,她就会出席今天下午的会议了.If she were not so busy, she would attend the meeting this afternoon. 2、对过去的虚拟,表示与过去的事实相反的假设时,条件状语从句的谓语动词用过去完成时,主句的谓语动词用would (should, could, might)+过去分词.见下表：条件状语从司的动词形式主句的动词形式If+主语+had+过去分词i(we)should+have+过去分词主语+could (might,could)+have ＋ 过去分词 3、表示与将来事实相反的假设,对将来表示怀疑,或将来的动作不太可能实现时,条件状语从句和主句的谓语动词有以下形式：（见表）条件状语从句的动词形式(三种)主句的动词形式(1)if十主语+动词过去式(be的过去式用were),通常要与一个表示将来的时间状语连用.(2)If+主语(任何人称和数)+should+动词原形(3)if+主语(任何人称和数)+were to+动词原形I(we)should+动词原形主语+would (might, could)+动词原形请看以下句子：1）If it rains tomorrow, our picnic will be put off. (说明：The weather has been very changeable these days.) 条件状语从句的谓语动词用现在时,表示说话人认为下雨的可能性很大.2）If it rained tomorrow, our picnic would be put off. (说明：The weather has been very good these days.) 条件状语从句的谓语动词用过去时,表示说话人认为下雨的可能性不大.3）If it should rain tomorrow, our picnic would be put off. (万一明天下雨,我们的野餐就推迟).条件状语从句的谓语动词用should＋动词原形,说明下雨的可能性很小或没有可能,如果下雨,那将是出乎意料的.4）If it were to rain tomorrow, our picnic would be put off.这句话与上一句意思几乎一模一样.If you should fail, what would you do?要是我明天真的见到她,我就把真相告诉她.If I were to see her tomorrow, I would tell her the truth.万一明天下雨,会议就推迟.If it were to rain tomorrow, the meeting would be put off.我打赌巴西会赢得世界杯.要是巴西输了,我就请你搓一顿.I bet Brazil will win the World Cup. If it should lose, I would treat you a meal.4、当条件状语从句表示的行为和主句表示的行为所发生的时间不一致时,动词的形式要根据它所表示的时间来调整.这与以上三种情况不同,虚拟语气的谓语动词形式没有遵循以上规律.For example:If you had worked hard, you would be very tired. (从句说的是过去,主句指的是现在.)If he had followed the doctor’s advice, he would be quite all right now.If I were you, I would have gone home. Now let’s do some translation:如果她过去没有刻苦训练的话,就不会跑得这么快.（从句动作指的是过去,主句指的是现在的情况）(Fact: She has trained very hard, so she is able to run very fast now.)If she hadn’t trained so hard, she wouldn’t be able to run so fast.5. 以上句型可以转换成以下形式：1）条件状语从句省略if：在书面语中,如果条件状语从句的谓语中有were, had 或should, 就可以省略if, 并将were, had 或should 放到句首,谓语主语之前,用 “Were/Had/Should + 主语”的形式.这种虚拟语气在意义上与带if 的条件状语从句相同.当然,如果从句没有were, had, 或should,就不能省略if.Now let’s look at some examples:If I were to do it, I’d do it some other way. →Were I to do it, I’d do it some other way.If you should fail, try again. →Should you fail, try again.If you had been here earlier, you would have seen him. →Had you been here earlier, you would have seen him.但是,If you came tomorrow, we would have the meeting.这句话if 就不能省略.而且,在虚拟条件状语从句中,省略了if的倒装形式的句首不能用动词的缩略形式.如我们可以说：Were it not for the expense, I would go to Italy.但不能说：Weren’t it for the expense, I would go to Italy.Please do not use “if”：如果我是你,我每天早上就早起床.Were I you, I would get up early every morning.要是明天有会议,我就会来.Should there be a meeting, I would come.2）用介词短语代替条件状语从句.（可以改为条件状语从句）.例如：Without air, there would be no living things.But for your help, I couldn’t have done it.Without electricity human life would be quite different today. Now let’s do some translation. 请用介词短语代替条件状语从句.要不是你的帮助,我就失败了.But for (except, without) your help, I would have failed.如果没有恰当的控制手段,核反应堆就会爆炸.Without proper means of control, a nuclear reactor would explode.3）用其他方式代替条件状语从句（可以改写为条件状语从句.）例如：It would produce bad results to do that. 用动词不定式 =If you did that/should do that, it would produce bad results.She would have come, but she wasn’t informed, nor invited. （用but.）=She would have come, if she had been informed or invited.A more responsible person would not have left the work half done. 一个更负责的人是不会把工作做到一半就不管的.(用比较级) ＝If you (he, she) were more responsible, you (he, she) would not have left the work half done. 我应该早点写完这封信,但我一直很忙. I should have written the letter earlier. But I have been very busy. 要能登上珠穆朗玛峰,那经历该多棒!It would be a fantastic experience to climb up to Mount Everest. 6、虚拟语气省略条件从句或主句表示虚拟语气的条件句的主句或从句有时可以省略,而省略部分的含义仍有所体现.1）省略条件从句,如：It would be very nice.You could have done it yourself. (省略If you had wanted to.上下文可以看出You didn’t want to.) (Fact: You didn’t do the work yourself because you didn’t want to.)I wouldn’t smoke. (省略If I were you.) (表面上说我,实际上说你.这是一种委婉的表达法.（Fact: You smoke very often. I advise you not to smoke any more.）2）省略主句：在强调条件从句时,常省略主句,这种句子常表示一种“已不能实现”的愿望,主要用于If only 引导的感叹句中.For example:If only he were here!If only I knew more!If only he had stayed with us! Now let’s do some translation:要是我听了他的建议就好了!If only I had taken his advice!我如果是一只鸟就好了!If only I were a bird.快用If only 造三个句子,表达你的愿望!If only I could live in a big apartment!If only I were a billionaire!If only I could marry her/him! （二）虚拟语气的其他句型和用法1、用在“wish+宾语从句”中,表示很难实现或不能实现的愿望,可以翻译为“但愿…”, “悔不该…”等.表示现在不能实现的愿望,从句的谓语动词用过去式；表示将来的愿望,从句的谓语动词用“would (could)+动词原形”；对过去的事情表示愿望,从句的谓语动词用 “had+过去分词” 或“could + have + 过去分词”.Wish 后面的宾语从句必须用虚拟语气,不管这个愿望是否能实现.如：I wish it were Spring all the year round.I wish you could go with us.We wish we had arrived there two hours earlier. Now let’s do some translation using “wish”:我要是Jane 就好了.I wish I were Jane.他真希望自己生活在中世纪.He really wishes that he were living in the Middle Ages.但愿北京整年是秋天.I wish it were autumn in Beijing all the year round.要是你能同我们一起过寒假就好了.We wish you would spend the winter vacation with us.我要是没有买这辆车就好了.I wish I had not bought this car. 注意：wish 与hope接宾语从句的区别在于：hope表示一般可以实现的希望,宾语从句用陈述语气.Wish表示很难或不大可能实现的愿望,宾语从句用虚拟语气.请比较：We hope we will succeed. (We don’t know if we will succeed.)We wish we would succeed. (We know we can hardly succeed.)2、用在as if/as though,或even if/even though引导的从句中: 这时,如果从句中表示的动作发生在过去,则谓语动词用had＋过去分词形式；如果指的时现在的状况,则用过去式(be用were)；指将来则用would(should, could)+动词原形.这里只看从句动作发生的时间,与主句的时态没有关系.3、在It is (high) time (that)…句型中,后面的从句的谓语动词常用过去式(be的过去式用were), 或用should+动词原形(should 不能省略)来表示.这句话的意思是“（现在）该…”.For example:It is high time that you got married.It is time that I bought a car.Now it is time that you made some sentences by using this pattern. Think about what you should do now. 该你用这个句型造几个句子了.It is high time that I should lose some weight.It is time that I bought an apartment.It is time that we took a rest.4、在 I would rather (that)…句型中,后面的从句的谓语动词用过去式(be的过去式用were).这句话的意思是“我宁可…”,表示说话人的意愿.I’d rather I were in the rain now.I’d rather you did not tell him.5、用在suppose开头的祈使句中,从句的谓语动词变化与as if后面的动词变化规律相同,用过去式、过去完成式、或过去将来式.意思是“假如…”,但suppose 是动词,不是连词.如：Suppose the boss walked in. What should I do?Suppose Saddam had not been captured. What would the U.S. do?Suppose Chen Shui-bian should declare Taiwan independent. What would China do?6、用在for fear that或lest引导的从句中,表示“怕…”“万一…”等意思.从句的谓语动词用should＋动词原形,should 可以省略.如：7. 在表示建议、要求、命令等意思的动词,如arrange, command, demand, desire, insist, order, propose, request, require, suggest, beg, move（提议）后面的宾语从句中,谓语动词用should + 动词原形,should 可以省略,而引导宾语从句的that 不能省略.医生建议,即使在节假日人们也不应该熬夜.Doctors suggest that people should not stay up late even on holidays. ：suggest 表示“暗示”时,宾语从句不用虚拟语气.Insist后面强调的是事实时,宾语从句也不用虚拟语气.如：The neighbor suggested that his wife was having an affair.He insisted that he was right.Mike insisted that he had never stolen anything.8、使用上述表示建议、要求、命令等意思的动词派生的名词,或在这些动词用作名词时,名词之后的从句用虚拟语气,即从句的谓语动词用should＋动词原形,should 可以省略.从句的引导词that 不能省略.这与上述第7项类似.如：Our suggestion is that education not be industrialized. = We suggest that education not be industrialized.The president’s decision is that the war against terrorism be launched at the right time. =The president decided that the war against terrorism be launched at the right time.9、上述动词在It is suggested that…, It is required that…, It’s requested that…, It’s ordered that…, It’s arranged that…句型中,that 之后的从句用虚拟语气,即谓语动词用should+动词原形, should 可以省略,但引导词that 不能省略.如：It was suggested that he attend the conference.It was requested that the trial be openly reported.10、在It’s important (imperative, necessary, essential, vital, desirable, advisable, better) that…句型中,that 引导的从句用虚拟语气,即谓语动词用should ＋ 动词原形,should可以省略.这个句型表示说话人的意见、要求等.For example:It is desirable that your wedding be postponed until next July.It is imperative that the board chairman be present at the board meeting.