IF虚拟条件句

1、虚拟条件句条件句有真实条件句和非真实（虚拟）条件句两种。真实条件句所表示的假设是有可能发生的， 而非真实条件句则通常表示一种假想，与事实相反或不大可能会发生：if i have time, i w川go with them.假若我有时间，我就同他们去。（陈述语气）if i were you, i would go with them.假若我是你，我就同他们去。（虚拟语气）虚拟条件句的三种基本类型：与现在事实相反、与过去事实相反、与将来事实相反。1 与现在事实相反：if条件句主句过去时（bewere）would/should/could/might+do sth.（1） .if i you, i

2、 it in a different way.（如果我是你，我会以另外一种方式做这件事）（2） .if i time, i it again.（如果我有时间，我会再读一遍）2.与过去事实相反：if条件句主句had done sth.would/should/could/might have done sth.（1） .if i his advice, i such a mistake.（如果我接受了他的建议，我就不会犯这样的错误了。）（3） .i him yesterday if i to the station earlier.（如 果我昨天早点到车站就可以看到他了。）3.与将来事实相反：i

3、f条件句主句（1）过去时（bewere）（2） .should do sth. would/should/could/might do sth.（3） .were to do sth.（1） .she won，come tomorrow. if she , i her my new computer.（如果她来我就给她看我的新电脑）（2） .if it rai n, the crops saved.（如果下雨的话这些桩稼就能 获救）4 错综虚拟条件句如果你昨天吃了药，你现在就会好多了。注意：a）主句谓语中的should主要用于第一人称后。 would, might, could的大致区别是：w

4、ould（would表结果） （might表可能） （could表能力）表示结果，might表示可能性，could表示能力、允许或可能性。比较：if you tried again , you would succeed.要是你再试一试，你就会成功的。if you tried again , you might succeed.要是你再试一试，你可能会成功的。if you tried again , you could succeed.要是你再试一试，你就能成功了。b）如果条件从句中有were,助动词had或should,可将if省略，而把were,had或should移 至主语之前。(1)

5、.were i a stude nt, i would study harder.(2) .were it to rain, the crops would be saved.should it rain,(3) .had he helped me, i would not have failed.(4) 蓄虚拟条件句1) but forwithout要是没有空气，人类将无法生存。要不是你及时的帮助，我们完成不了这项艰巨的任务。2) otherwiseoror else; buthe was on bus in ess in beiji n at that time; otherwise (他

6、可能就帮我们了 ).i am really busy, otherwiseor or else i (会b艮你一起去另b里)i (原本会去参力口你的生日会的),but my boss made me work overtime.exercises:1) if it rain tomorrow, we will have a picnic.a. won train b. does ntra in c. didn r rain d. not rain2) if iyou, ithe en glish club.a. was, would b. were, would c. am, will d.

7、am, would3) if iwith her last summer, iwith her nowa. worked, am gett ing on very well b. had worked, would get on very wellc. had worked, would have got on very well d.had worked, will get on very well4) if i that she was ill, i would have gone to see her.a. knew b. knowc. have knownd. had known5)

8、without your en courageme nt and support, i.a. shouldn succeeded b. wouldn succeeded c. wouldn have succeededd. wouldn r have succeeded6) if there were no subjunctive mood, english much easier to learn.a. could have bee n b. would be c. will be d. would have bee n7) , i would tell her the secret.a. if she would comeb. should she to comec. were she to comed. would she come8) the heavy rain, we wouldn have arrived late.a. if it weren *forb. if it hadn been forc. in spite ofd. with9) he much, otherwise he would have gained weight.a. didn teat b. doesn c. had