1、真实条件句和真实条件句和虚拟条件句虚拟条件句1.2.1.表示客观事实或真理表示客观事实或真理 If you freeze water, it turns to ice. If you eat a lot of chocolate, you put on weight. 从句从句 主句主句 if+一般现在时，一般现在时一般现在时，一般现在时3.2.表示将来可能发生的事表示将来可能发生的事 If he fails in the exam, he will let his parents down. You will certainly succeed if you keep on trying.
2、从句从句 主句（陈述句）主句（陈述句） if+一般现在时，一般将来时（一般现在时，一般将来时（will+动词原形）动词原形）4.3.给某人提建议或命令某人做某事给某人提建议或命令某人做某事 If you feel sleepy, go to bed. If you want to know how it works, read the instructions. 从句从句 主句主句if+一般现在时，祈使句一般现在时，祈使句5.If引导的虚拟条件句，即非真实条件句，表示条引导的虚拟条件句，即非真实条件句，表示条件句所表示的条件根本不可能实现或实现的可件句所表示的条件根本不可能实现或实现的可能性很
3、小。根据动作发生时间的不同，含有非能性很小。根据动作发生时间的不同，含有非真实条件句的复合句的主从句的谓语动词采用真实条件句的复合句的主从句的谓语动词采用不同的表达方式。具体分为三种情况：不同的表达方式。具体分为三种情况：6.时间时间从句从句主句主句与与现在现在事实相反事实相反过去式过去式（be 通常用通常用were） should would could +动词原形动词原形 might与与过去过去事实相反事实相反 had+过去分词过去分词 should would could +have+过去分词过去分词 might与与将来将来事实相反事实相反 过去式（过去式（be 通常通常用用were）
4、should+动词原形动词原形 were to+动词原形动词原形 should would could +动词原形动词原形 might7.一、与现在现在事实相反1.If I knew his telephone number, I would tell you .2.If I were you ,I wouldnt be so proud.8. 二、与过去过去事实相反1.If he had taken my advice, he would not have made such a mistake.2.If I had got there earlier, I would have met h
5、er.9. 三、与将来将来的事实相反1.If there were a heavy snow next Sunday, we would not go skating.2.If she should come, I would tell her about the matter.10.1. The printer is of good quality. If it _break down within the first year , we would repair it at our expense.A. would B. shouldC. couldD. might11.2._,the f
6、orest fire would have been discovered much earlier.A. But for their careB. If they were careful C. Without their careD. If they had been more careful12.4.The weather has been very hot and dry.Yes. If it had rained even a drop, things would be much better now! And my vegetables_.A. wouldnt dieB. didn
7、t dieC. hadnt diedD. wouldnt have died13.5.Had I known about the computer program, a huge amount of time and energy_.A. would have been savedB. had been savedC. will be savedD. was saved14.6.If we _ the other road, we might have arrived here in time for the meeting.A. takeB. had takenC. tookD. have taken 15.16. 17.
