四级重点语法及句式.doc

重点语法及句式1虚拟语气英语中一共有三种语气：陈述语气，祈使语气，虚拟语气虚拟语气是一种特殊的谓语 动词形式，是讲话人在主观上而不是客观上対事物的看法和态度，表达的是假设、愿望、建 议、命令、祝福等虚拟语气可用于条件状语从句、名词性从句（宾语从句、主语从句、表 语从句、同位语从句）、以及其他结构中虚拟语气的运用很大程度上和其所在的句型有关1）虚拟语气在条件句中的应用英语中的条件句主要有两类：真实条件句和虚拟条件句在虚拟条件句中，主句与从句 的谓语动词要用虚拟语气，具体体现在以下儿个方面：（1） If虚拟条件句这是虚拟语气的基本用法If虚拟条件句中，主句与从句的谓语动词形式可列表如下:假设类型条件从句的谓语动词形式主句的谓语动词形式与现在事实相反动词过去式（be多用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) + have+过去分词与将来事实相反动词一般过去式 were （0+动词原形would (should/ could/might) + 动词原形①与现在事实相反If he were here, everything would be all right.%1 与过去事实相反If the United States had not entered the Second World War, probably the 1940 unemployment rate of 14%would have risen still furthe匚%1 与将来事实相反It is said Tom will go to an interview tomorrow. If he were to come tomorrow, I would ask him to go to your place.If he were here this evening, he might be able to help・(2) 错综时间虚拟语气(主从句时间不一致情况下的虚拟语气)有时条件状语从句中动作发生的时间与主句中动作发生的时间不一致，这时谓语动词的 形式应根据它所表示的时间加以调整。

例如：%1 从句与过去事实相反，主句与现在事实相反If I had worked harder at school, I would be sitting in a comfortable office now.%1 从句与现在事实相反，主句与将来事实相反If you hesitated this moment, you might suffer in future・(3) 虚拟条件句的倒装形式在艰拟条件句中，如果省略if,从句要用倒装形式，即把谓语助动词had, were, should, could等提前至句首，其他词序不变，例如：%1 与现在事实相反Were you (=If you were ) free to choose among all the cars available today, what type of automobile would you buy?%1 与过去事实相反The millions of calculations involved, had they (= if they had) been done by hand, would have lost all practical value by the time they were finished.%1 与将来事实相反Were he （=If he were） to start out today, he would get there by Thursday.（4）含蓄虚拟条件句在表示假设的鹿拟语气中，有吋假设的条件并不以条件从句的形式表达，而是通过上下 文或句中内在的逻辑关系，或用其它形式表达出來，我们称之为”含蓄虚拟条件句“。

常见的 用来表示含蓄虚拟条件的词有：but for, but that, without, otherwise, or, under more favorable conditions, given 等 o 例如：But forAVithout your help, we would n't have accomplished the task on time.He hadn't had food for two days, or/otherwise he wouldn't have fainted out at work.Given more time, we could have done the work much better.Under more favorable conditions, we could have achieved success・2）虚拟语气在名词性从句中的应用（1） It is （was）+形容词（或过去分词）+that...结构中的虚拟语气在“Itis（was）+形容词（或过去分词）+that ”结构中，某些表示愿望、建议、命令、可能、适当、迫切、重要等意义的形容词或过去分词后的主语从句的谓语也要用虚拟语气, 其形式为should +动词原形或直接用动词原形（美式英语中省去should）o常用的形容词和过去分词如下:natural （自然的） necessary （必须的）appropriate （适当的） important （重要的）advisable （合适的） urgent （急迫的）preferable （更可取的） essential （必要的）vital （极重要的）compulsory （必须的）crucial （紧急的）imperative （必需的）urgent （紧迫的） essential （木质的） required （必须的）advisable （应该的） probable （很可能的） demanded （要求）incredible （惊人的） possible （可能的） requested （被请求的）strange （奇怪的） desirable （合意的） desired （期望的）suggested （建议）recommended （推荐的）ordered （命令） proposed （建议的）decided （确定的）It is vital that enough money （should） be collected to fund the project ・From the standpoint of the long-term strategic interest of the West, it is imperative that their territorial unity （should） be a safeguard・注：上述所列形容词后用that引出的宾语从句中，谓语动词也要用虚拟语气，例如：I don’t think it advisable that Tom be assigned to the job since he has no experience.（2） suggest, propose等动词后所接宾语从句中用虚拟语气表建议、命令、要求的动词引导的宾语从句中，从句的谓语动词常用虚拟语气，其形式 为shoukl+动词原形，或直接用动词原形。

这些常见的动词如下：suggest propose recommend move （提议）advise insist urge（极力主张）require request dema nd desire order comma nd decide intend preferThey demanded that the right to vote （should） be given to every adult man.The committee recommends that the maMer （should） be discussed at the next meeting.（3） suggestion, proposal等名词后所接同位语或表语从句中用虚拟语气表建议、命令、要求的名词后所接的同位语或表语从句中，从句的谓语动词常用虚拟语 气，其形式为should +动词原形，或直接用动词原形这些常见的动词如下：order request requirement insistence suggestion command necessity importance idea plan motion（提议）proposal（建议）recommendation（建议）rcsoluiion（决定，决议） We are all for your proposal that the discussion （should） be put off.My idea is that we （should） get more people to attend the conference・3）虚拟语气在其他句型中的应用(1) 动词Wish所接宾语从句中的虚拟语气当动词wish后面接that引导的宾语从句(that经常被省略)吋，宾语从句中的谓语动词要 用虚拟语气，表示一种不可实现的愿望。

与现在事实相反时，从句的谓语动词用一般过去时 (be用were的形式)；与过去事实相反时，从句的谓语动词用过去完成时；与将來事实相 反时，从句的谓语动词常用would+动词原形I wish I were as strong as you.She wishes that we hadn't sent her the candy yesterday because she's on a diet.I wish you would stay here longer.(2) as if/as though引导的从句中的虚拟语气在as if (as though)引导的方式状语从句或表语从句中，谓语动词有时用虚拟语气若与 现在事实相反，谓语动词用一般过去时；若与过去事实相反，用过去完成时They treat me as though I were a strangerHe was shaking with fright as if he had seen a ghost.(3) would rather, would sooner, had rather 引导的从句中的虚拟语气would rather, would sooner, had rather用来表达主观愿望，意为"宁愿宁可这些短 语所引导的宾语从句中需用虚拟语气。

与现在或将来相反时，谓语动词用过去时，与过去事 实相反，谓语动词用过去完成吋表示You don't have to be in such a hurry. 1 would rather you went on business first.I'd rather he hadn't told me about it.(4) It is (high, about) time所接从句中的虚拟语气It is (high, about) time所接从句中的谓语动词应使用一般过去时表示虚拟语气，指现在 或将来的情况，表示“该(必须)做……"It's time you looked ahead and made pl。