2.1. 与过去事实相反

　　1). If I had had much money at that time, I would have bought you what you want.

　　2). If you had been more careful, the mistake might have been avoided.

　　3). If you had taken my advice, you wouldn't have made such a mistake.

　　4). We wouldn't have succeeded if it had not been for their help.

　　5). If you had been here yesterday, you would have met the film star.

　　6). If I had known more about giving first aid, I could have helped them.

　　7). If you had got up earlier, you would have caught the train.

　　8). If we had had enough rain last year, we could have gained a good harvest.

　　9). If you had worked a little harder, you could have passed the final examination.

　　10). If they had invited her to the party, she would have attended it.

　　2.2.与现在事实相反

　　1). If I were you, I would go there at once.

　　2). If my classmates were here, they would help me.

　　3). If I were you, I would accept the job.

　　4). If classes were smaller, children would learn more.

　　5). If I were ten years younger, I would start all over again.

　　6). If I had enough money, I would buy a large house.

　　7). If I had time, I would go shopping with you.

　　8). If I knew all the answers to all your questions, I would be a genius.

　　9). If he were here now, we would ask him about it.

　　10). If I had time, I would study French.

　　11). If I knew her number, I could ring her.(可惜我不知道)

　　12). If there were no gravity, we should not be able to walk.(实际上地球引力始终存在。)

　　13). If I knew the answer, I would tell you.(实际上我确实不知道，所以肯定不能告诉你。)

　　14). If I had money on me, I would lend you some.

　　15). We would not be able to walk if there were no friction.

　　16). If you were in my position, what would you do?

　　17). If they treated me as a slave, I had to resign.

　　18). If there were no examinations, we should have a much happier time.

　　19). If wishes were horses, beggars might ride.(如果幻想能成为马匹，叫花子们都有了坐骑。)

　　20). Life might be too dull if it had no difficulties in it.(倘若生活中没了困难，就会过于平淡。)

　　2.3. 与将来事实相反

　　1). If it rained / should rain / were to rain tomorrow, we would have a rest.

　　2). If the sun were to rise from the west, I would marry you.

　　(注意：对将来虚拟的条件从句中，在实现的可能性方面过去式did最大，should do中等，were to do最小。如本句太阳没有可能从西方升起，所以本句用were to最恰当。)

　　3). If I were to meet her tomorrow, I would ask her about it.

　　4). If green plants should disappear some day, there would hardly be any life on the earth.

　　5). If I were to do the work, I would do it in a different way.

　　6). If it should(were to) rain this afternoon, the football match would be put off.

　　7). If you missed the film this evening, you would be sorry for it.(如果今晚错过了这场电影，你会遗憾的。实际上，你不会错过。)

　　8). If I were to see her tomorrow, I would invite her home.

　　9). If you lived there for several months, you would change your mind about the place.

　　10). If things were to be done twice, all would be wise.(如果事情能被做两次，人人都会变得明智。)

　　2.4. 混合型

　　1). If you had followed the doctor's advice, you would be much better now.(过去→现在)

　　2). If you had worked hard, you would be a college student now.(过去→现在)

　　3). If you had listened to me, you wouldn't be in such trouble now.(过去→现在)

　　4). If you had got six more votes yesterday, you would be our chairman now.(过去→现在)

　　5). If I had earned much money last summer, I would go on a vacation next month.(过去→将来)

　　6). If you hesitated this moment, you might suffer in future.(现在→将来)

　　7). If the doctor had come sooner last night, Tom would be alive today.(过去→现在)

　　8). If I were you, I would have gone to her birthday party.(现在→过去)

　　9). If it had rained last night, the ground would be wet now.(过去→现在)

　　10). If you hadn't lent me some money, I couldn't have bought the new house and most likely I wouldn't be still living in the dangerous house now.(过去→过去→现在)

　　2.5. if的省略与条件句的倒装

　　1). Were I you, I would have accepted the job.

　　2). Were she here, she would support us.

　　3). Were you to go fishing with me, you would have a much happier time.

　　4). Were men angels, no government would be necessary.(如果人人都是天使，政府就没有必要了。)

　　5). Were she my daughter, I wouldn't allow her to study abroad.

　　6). Had you come earlier, you would have met my girlfriend.

　　7). Had I time, I would come.(本句中had是实意动词，而非主动词。)

　　8). Had I been informed earlier, I could have done something to prevent it from happening.

　　9). Many persons in the worls would have succeeded had they not wasted their valuable time.

　　10). Should it be fine tomorrow, we would go outing.

　　11). Should you change your mind, no one would blame you.

　　12). We would gone to your birthday party had you invited us.

　　13. I would go should it be necessary.

　　14). What would have happened had Bob walked farther, as far as the river bank?

　　15). Had it not been for you, I would have lost my way.

　　16). Were it not for water, no plant could grow.

　　17). Be they common people or high-ranking officials, they stand equal before the law. (Whether they be…)

　　18). Be the weather what it may, I will leave tomorrow. (Whether the weather be what it may, …)

　　注意：在这一结构中，若条件句为否定句，not应被放在主语之后，而不能缩写成weren't, shouldn't或hadn't而置于居首。如例15，16。

　　2.6. 含蓄型：

　　A. with ：“要是有，如果有”，表示与现在事实相反的假设。

　　1). With your help, we would have worked out the problem.

　　(要是有你的帮助，我们早就解出这道题了。实际上你没有帮助我们，我们也没有解出这道题。)

　　2). With a little asssistance, Alexander would have succeeded.

　　3). With better equipment, we could have done it better.

　　B. a. without / but for / if it were not for(were it not for) / if it hadn't been for(had it not been for) / in the absence of + Sb. /Sth.

　　b. but that + 句子;

　　注意: a.b. 都表示“要不是，若非，如果没有,如果不是”, 表示与现在事实相反的假设。

　　1). Without your help, I wouldn't have made such rapid progress.

　　2). Without the programmer(程序编制人员), the computer would be useless.

　　3). Without sunshine, nothing could grow on earth.

　　4). Without water or air, nothing could live.

　　5). Without contradiction nothing could exist.(没有矛盾，就没有世界)

　　6). Without him, we would have failed.

　　7). Without the difficulies we would not know great men's toughness.(如果没有困难， 我们就不会了解伟人的坚韧性格。)

　　8). I would never make it without the havits of order and diligence.(假如没有按部就班和勤奋的习惯，我就不会成功。)

　　9). Without challenges, Obama would never have been President of the United States.

　　10). Without steel, there would be no modern industry.(没有钢，就没有现代工业。)

　　11). But for the rain, we should have had a pleasant journey.

　　12). But for your timely rescue, the boy would have drowned.

　　13). But for friction, people could neither walk, nor even stand up.

　　(注：以上例句1-13without, but for都可互换，并可替换为in the absence of; 若是对现在或将来的虚拟，可用If it were not for替换;若是对过去的虚拟则可用If it had not been for来替换。)

　　14). But that he saw it, he could not have believed it.

　　15). The little girl would have fallen into the river but that the PLA man caught her.

　　16). But that you didn't let me take that cup of tea I would have been posioned to death.

　　17). She would have come to see you that day but that she was ill. (=But for her illness)

　　18). But that it snowed heavily, they could have arrived there earlier. (=But for the heavy snow, …)

　　19). She would have bought the book but that she had no money then.

　　20). If it weren't for my job, I would come with you.

　　21). If it were not for his wife's money he would never be a mayor.

　　22). If it hadn't been for the doctor's care, I should not be speaking to you now.

　　23). If it had not been for you, I could not have worked out the problem.

　　C. or, or else, otherwise;

　　1). I didn't catch the bus, otherwise I wouldn't have missed the film.

　　2). I got up too late, otherwise I wouldn't have been late for the meeting.

　　3). She wasn't feeling very well. Otherwise she wouldn't have left the meeting so early.

　　4). I was ill that day. Otherwise I would have taken part in the parade(游行).

　　5). I am busy now. Otherwise, I would help you.

　　6). He can't have written to me, otherwise I would have got his letter by now.

　　7). He told me of your arrival, or I would have known nothing about it.

　　8). The soldier fled away, or he would have been killed.

　　9). I didn't know that he was a liar, or else I wouldn't have believed him.

　　D. 通过上下文推断，没有引导词，真正的含蓄。

　　1). Born in better times, he would have been a scholar(学者).

　　2). I would do so in your position.

　　3). Given more time, we would do it better.

　　4). Unless you had done it earlier, you would have failed.

　　2.7. suppose(that), supposing(that); provided (that); assuming (that); on condition that; given that

　　1). Suppose/supposing that there were no gravity, objects would not fall to ground when dropped.

　　=If there were no gravity, objects would not fall to ground when dropped.

　　2). Supposing you couldn't write, what would you do?

　　3). Children were permitted into the hall for the film provided (that) they did not make any trouble.

　　4). The guards allow the tourists to go into the woods on condition that they (should)do no harm to the animals.

　　(on condition that = only if, 它所引导从句的谓语动词的语气可陈述，可虚拟，但均表示一个真实条件。)

　　5). Given that he doesn't agree to do it, we shall do it alone.

　　(given that表示一个真实条件，其从句谓语动词用陈述语气。)