初中英语：语法知识虚拟语气第十节.docx

美联英语提供：初中英语：语法知识虚拟语气 第十节两分钟做个小测试，看看你的英语水平http:/m.meten.com/test/waijiao.aspx?tid=16-73675-0词类、句子成分和构词法第十节 虚拟语气虚拟语气是说话人为表示一种假设的情况或一种主观的愿望，即认为动词所表示的动作或状态并非事实或主观设想时所用的语气。 虚拟语气的形式与用法： 1有一类虚拟语气的形式称为be型虚拟式，即不管主语是什么人称，动词一律用原形(或should+动词原形)。 以下几种情况必须用be型虚拟式：1)一些表示命令，要求，决定，建议等概念的动词后由that引导的宾语从句中，必须用be型虚拟式。这类动词有：ask (要求)，advise(建议)，command (命令)，decide (决定)，demand (命令)，insist (坚持)，move (提议)，order (命令)，propose (提议)，recommend (建议)，request (要求)，require (要求)，suggest (建议)，urge (极力主张)。例如：We strongly suggest that he (should) be told about it earlierThe doctor insisted that his patient take it easy for three monthsI require that they come by tenI recommended that each competitor receive $100The judge ordered that the witness tell the truth2)一些表示主张、要求、命令、愿望、建议等概念后的主语从句中，必须用be型虚拟式。此类词主要有：It is necessary, essential (重要的)，advisable(应该的)，appropriate(合适的)，desirable (值得的)，fitting (合适的)，important (重要的), imperative (必须的)，obligatory (必须的)，proper (适当的)，strange (奇怪的)，urgent (紧要的)，vital (极重要的) that；It is (was, has been) suggested (decided，desired，ordered，proposed，requested) that 例如：It is highly desirable that a new president be appointedIt is important that everybody have his health checked yearlyI think it advisable that he leave soon.It is decided that you be the first one to do the experiment3)一些表示主张、要求、命令等概念的名词后面由that引导的同位语从句中，通常用be型虚拟式。这类词主要有：advice，command，importance，idea，insistence，motion (提议)，necessity，order，plan，proposal (建议)，recommendation (建议)，request，requirement, resolution (决议)，suggestion，understanding (协议)。例如：My suggestion is that he be sent to help this group4) 在lest，for fear that或in case表示“生怕，以防万一，免得”引导的从句中，从句常常用should。例如：He studied day and night，lest he should fail in the testWe dare not play jokes on him for fear that he should become angryBe quiet in case you should wake the baby5)某些表示祝愿、诅咒、禁止等的语句中用be型虚拟式。例如：God bless you!God damn you!Long live Chairman Mao!Heaven forbid!2下列两种句型，从句总是用一般过去式表示虚拟语气。1) It is (high) time that (该做，必须做)，丛句用一般过去时。例如：It is time that he went to bed nowIt is high time that this wrong spending was checked2) would rather, would sooner, had rather这些表示“宁愿”的短语后面的从句中的谓语动词应使用一般过去时表示虚拟语气。例如：Dont come today1 would rather you came tomorrowHe had rather his children didnt make so much noiseI would sooner we had dinner now3If引导的条件状语从句的虚拟语气用法If引导的从句的虚拟语气主要有三种结构：1)与现在情况相反：主句谓语用“wouldcouldmight +动词原形”，从句谓浯用“动词的一般过去式”(be的过去式一律用were)。例如：If I had time，I would go with youIf I were you，I might refuse the engagement2)与过去情况相反：主句谓语用wouldcould + havedone，从句渭语用“动词的过去完成式”。例如：If I hadnt lost my way，I would have caught the last trainThey would have arrived earlier if there had been no storm3) 与将来情况相反：主句谓语用wouldcouldmight +动词原形”，从句谓语用were toshould+动词原形”。例如： If you were to see Mary，what would you tell her?If I were to do it，I would do it in a different wayIf it should rain tomorrow，I would stay at home4) 省略if的虚拟语气句。 虚拟条件从句中的谓语动词如果是were，should，had等词时，可以省略连词if, 但必须将were，should，had等词移至主浯前形成句子倒装。例如：Had he been given some information about it, he could have answered the questionWere you to get up earlier，you wouldnt be late4Wish后的宾语从句中的虚拟语气用法动词wish后跟由that引导的宾语从句(that经常被省略)要用虚拟浯气表示一种不可实现的愿望。1)宾语从句用过去式表示与现在事实相反。例如：I wish I had enough time to finish my homework todayMy brother is in Europe on vacation，but I wish he were here with me2)宾浯从句用过去完成时表示与过去事实相反。例如：I wish 1 had gone to the movies with you last nightI wish Professor Lee had taught me this equation3)宾语从句用“would/could +动词原型”表示一种愿望或要求。例如：I wish that you would come next timeShe wishes that you could stay here longer 5由as ifas though引导的状语从句表示方式时，意思是“好像”，这时从句中的谓语动词应用虚拟语气。 1)状语从句用过去式 (be用were的形式)表示与现在的事实相反。例如：He treats me as if I were a stranger2)状语从句用过去完成式表示与过去的事实相反。例如： He talked as if he had been to Australia.6.介词或介词短语表示虚拟：有时假设的情况并不以条件从句表示出来，而是通过一个介词或介词短语来表示，或通过上下文表示出来。如but for，but that，with，without，otherwise，on condition (that)，in case of，supposing，on the understanding that等表示让步假设。例如：If I hadnt got your help，I wouldnt have found my present job= Without your help，I wouldnt have found my present job= But for your help，1 wouldnt have found my present job= But that you helped me，I wouldnt have found my present job7. 错综虚拟条件句：一般来说，主句和从句的谓语动词形式应前后呼应。但是有时主句和从句的动作发生的时间不一致，谓语动词的形式应作相应的调整，如：从句用过去虚拟语气，主句用现在虚拟语气(通常可以根据时间状语而定)。Had it not been for the timely investment from the general public，our company would not be so thriving as it isIf Paul had receivd six more votes in the last election，he would be our chairman nowIf you had studied the problem carefully yesterday，you would not find any difficulty now.8此外，还有省略了结果主句的虚拟语气if only结构，一般表示愿望。if only从句中的时态有三种：V+ed；be用were；情态动词用couldwouldmight+v。例如：If only he saw me now! 要是他现在能看到我那该多好!If only she had not been married! 要是她没有结过婚就好了!If only the committee would approve the regulations and put them into