1、Unit 21 Human BiologyLesson 1 Super AthletesGrammar : Conditionals Revision1条件句有两类，一类是真实条件句，一类是虚拟条件句。2如果假设的情况是有可能发生的，就是真实条件句（Zero conditional）。真实条件句中的谓语用陈述语气。Eg。If it doesnt rain tomorrow, we will go to the par.如果明天不下雨,我们就去公园.3.如果假设的情况是过去或现在都不存在的,或将来不大可能发生的,则是虚假条件句,共有三种情况.Eg. If he had seen you yest
2、erday, he would have asked you about it.如果他昨天见到你,他会问你这件事的.(事实上他昨天没有见到你,因此也未能问你这件事.)4.在含有虚拟条件句的复合句中,主句和从句的谓语都要用虚拟语气.虚拟条件从句和主句的动词形式列表如下:时间从句主句与现在事实相反动词过去式(be动词的过去式一般用were)would(should/could/might)+动词原形与过去事实相反Had+过去分词would(should/could/might)+had过去分词与将来事实相反动词过去式/should+动词原形were to+动词原形would(should/coul
3、d/might)+动词原形5.虚拟条件句的用法1) 表示与现在事实相反的假设和结果(1st conditional)Eg. If I were you,I should/could/would/might tell him the truth. 如果我是你,我就会/可能对他说实话. If he had time, he would/could/might go with you. 如果他有时间,他就会/可能和你一起去. If my brother were here,everything would be all right. 要是我哥哥在这儿,一切都没问题了.2) 表示与过去事实相反的假设和
4、结果(2nd conditional)Eg. If you had taken my advice, you wouldnt/couldnt have failed in the exam. 如果你按照我的建议去做,你不会/不可能考试不及格. If I had had the money last week, I should/would/could/might have bought a car. 如果我上星期有了这笔钱,我就会/可能买辆车. She would/could/might have telephoned you immediately, if she had won the g
5、ame. 如果她比赛赢了,她就会/可能给你打电话. If you had come a few minutes earlier, you would/could/might have met the famous singer. 如果你早来几分钟的话,你就会/可能会见到那个著名的歌唱家.3) 表示与将来事实可能相反的假设和结果(3rd conditional)Eg. If it were Sunday tomorrow, I should/would/could/might go to see my grandmother. 如果明天是星期天,我就/可能去看我的奶奶. If it were t
6、o snow this evening,they would not go out. 如果今晚下雪,他们就不出去了. If it should rain,the crops would/could/might be saved. 如果下雨,庄稼就一定/可能有救.6.主,从句的动作发生时间不一致的情况(mixed conditional) 有时条件从句中的动作和主句中的动作发生的时间不一致,这时动词的形式要根据它所表示的时间加以调整.Eg. If you had listened to the doctor, you would be all right now. 如果你当初听了医生的话,身体现在就好了.(从句动作指过去,主句动作指现在) If you had practiced speaking English more, you would be able to speak it fluently.如果你多练习讲英语,现在就能讲得很流利了.