if引导的虚拟条件句.ppt

虚拟语气-if 引导的虚拟条件句虚拟语气(if 条件句)含含义义：其假：其假设设是是不可能或不大可能不可能或不大可能发发生或生或实现实现的；的；主从句皆主从句皆须须用虚用虚拟拟 If the working conditions are not too bad,I will accept the job.（真（真实实条件句：条件句：对现对现有事有事实实的一种的一种陈陈述，使用的是述，使用的是陈陈述述语语气）气）-表达一种表达一种看法（工作条件状况未知）看法（工作条件状况未知）If the working conditions were not too bad,I would accept the job.（非真（非真实实条件句条件句-虚虚拟语拟语气）表达一种假气）表达一种假设设（与事（与事实实相反相反-工作条件已工作条件已经经很糟糕了）很糟糕了）If 引导的虚拟条件句的三种类型带if的虚拟条件句省略if的虚拟条件句隐藏if的虚拟条件句与与现现在在事事实实相相反反：if条条件件句句用用一一般般过过去去时时（动动词词be用用were），主句用），主句用would(should/could/might)+动词原形动词原形、带if的虚拟条件句eg:I am sorry I am very busy just now.If I had time,I would certainly go to the movies with you.If you could bear the loneliness,you might succeed.与与将将来来事事实实相相反反(推推测测将将来来)：if 条条件件句句中中用用过过去去时时，或或 should/were to+动动 词词 原原 形形，主主 句句 用用 would(should/could/might)+动词原形。动词原形。eg.If she were here this evening,we would go shopping.（从句：一般过去时）If Mary were to marry Jack,she would be happy.（从句：were+动词不定式）If she should know it,she would tell me.(But I doubt)（从句：should+动词原形）If we hadnt made adequate preparations,the party wouldnt have been so successful.The flood might have caused great damage to the people,if we hadnt built so many dams.与与过过去去事事实实相相反反：if 条条件件句句中中用用过过去去完完成成时时，主主句句用用would（should/could/might）+have+过去分词过去分词。条件从句条件从句结果主句结果主句与现在事实相反与现在事实相反If +主语主语+过去式过去式 主语主语+would/should/could/might do 与将来事实相反与将来事实相反If+主语主语+过去式过去式主语主语+would/should/could/might dowere to do/should/could do)与过去事实相反与过去事实相反If+主语主语+had+过去分词过去分词主语主语+would/should/could/might have doneIf引导虚拟条件句中的谓语动词变化引导虚拟条件句中的谓语动词变化与将来事实相反时从句中的三种谓语v变形：一般过去时were+to doShould/could do注：这三种均可用，不同的是在表示推测将来的时候，可能性的程度不同。If it snowed tomorrow,I should/would stay at tomorrow.（常用形式）If it were to snow tomorrow,.（可能性较小）If it should snow tomorrow,（可能性较大）.虚拟条件句中if的省略或隐藏1.省略if 的虚拟条件句隐藏 if 的虚拟条件句-无“条件”的虚拟语气句子1.省略if 的虚拟条件句(主要用于书面语)在虚拟条件句中，有时可将引导虚拟条件句的连词if省略，但此时应用倒装倒装句型，即将从句中的were,should,had 等提到句首。1.省略if 的虚拟条件句如果她在这里，她也同意的。If she were here,she would agree too.Were she here,she would agree too.假若明天下雨，我们只好推迟这场比赛。If it should rain tomorrow,we should have to put off the match.Should it rain tomorrow,we should have to put off the match.1.省略if 的虚拟条件句要是我们当时早点找到他的话，我们就可以救活他。If we had found him earlier we could have saved his life.Had we found him earlier we could have saved his life 1.省略if 的虚拟条件句的否定式注意，如果条件从句的谓语为否定式，其中的否定词not应应置于主置于主语语之后之后，而不能与were,should,had 等缩略成Werent,Shouldnt,Hadnt而置于句首。我如不是警告了你，你就可能丧命了。正：If I hadnt warned you,you could have been killed.正：Had I not warned you,you could have been killed.误：Hadnt I warned you,you could have been killed.1.省略if 的虚拟条件句有时省略if后提前到句首的had可能不是助动词，而是实义动词。如：Had I time,I would go with you.假如我有时间，我就同你们一起去。句中的had不是构成过去完成时的助动词，而是表示“有”，如果不省略if，其完整形式为：If I had time,I would go with you.Exercises：He must have had an accident,or he then_.Awould have been here Bshould be hereChad to be here Dwould be there 答案为A。or 在这里隐含了与过去事实相反的虚拟语气，表示if he had not had an accident,所以其后的主句用would have done 而不用其它的。Exercises：1.Given more time and money,he _ better than what it is.A.did B.have done C.could have done D.would do2.If you explained the situation to your solicitor(律师)，he _ able to advise you much better than I can.(2005)would be B.will have beenC.was D.were Exercises：3._ you _ further problems with your printer,contact your dealer(经销商)for advice.A.If,had B.Have,had C.Should,have D.In case,had