英语虚拟语气的用法详解

精选文库虚拟语气的用法荟萃一：概念：虚拟语气是指和现实情况相反的假设，是对真实情况的主观臆想或是一种主观愿望。二：虚拟语气涉及的情况：1) 用在由if引导的非真实条件句中。条件句分为真实条件句和非真实条件句。A)真实条件句：即条件是可实现的客观事实或者真实情况。如：If you heat ice, it melts.(融化)If I make a promise, I keep it.If we catch the early bus, we will(shall,can, may,)get there by lunch time.If it is fine tomorrow, we can play basketball.(客观事实)If it rains, I go to school on foot.B)If 引导的非真实条件句中，即虚拟条件句中。主要涉及到对三种情况的虚拟：对过去的虚拟；对现在的虚拟；对将来的虚拟。谓语动词的时态变化符合“倒退一步法”。对过去真实情况的虚拟，或者对过去事实完全相反的假设：公式：if had + V-ed分词（从句）, Would（could,might,should） + have+ V-ed分词 （主句）如：If we had started earlier, we should not have missed the train.If she hadnt been ill, she might have come.If they had helped us, we would have finished the task. (实际上没帮)If I had made good prepatation, I wouldnt have lost the job. 对现在真实情况的虚拟，或者对现在真实情况相反的假设：公式：If .+V-过去式(be多用were),.+would/should/could/might + 动词原形If I were a bird, I would fly to the top of Mount Hua.If I had time, I would go to the movies with you. (实际上没时间)If I had enough money, I would buy that new toy for you.对将来情况相反的假设：公式：If 。+动词过去式/should +动词原形/were to +动词原形,。+would/should/could/might +动词原形If it should/were to/ rain tomorrow, I would stay at home.(下雨的可能性很小)If Kobe should come to our village, I would take photos with him.注意：虚拟语气的倒装语序：上述(1),(2),(3)三种时态的虚拟句中,如果if从句里含有should, had, were或其他助动词,则可将从属连词if省去,将助动词.情态动词.be或have放在句首形成部分倒装.If I had time, I would have done that yesterday.=Had I had time, I would have done that yesterday.If I were you, I would go to the party.=Were I you, I would go to the party.If it should rain tomorrow, I would stay at home=Should it rain tomorrow, I would stay at home.2） 错综时间if虚拟条件句 通常情况下,在非真实条件句中主句和从句的谓语动词所指时间是一致的, 但有时也可能指不同的时间,这时要根据上下文的意思采用不同的谓语动词形式.如： If I were you, I would have taken his advice. (从句指一般情况, 主句指过去)If I had taken my raincoat with me this morning, I would not be wet now. (从句指过去,主句指现在). If I had bought that ticket last night, I would go to the theater(剧院) with you tomorrow.3） that从句及其他特殊句型中的虚拟语气：A)在suggest, order（命令） demand（要求）,request（要求），require（要求）， propose（建议）,move（提议）， command,（指挥） , recommend（推荐）, decide, insist（坚持）, desire（渴望）, urge（督促）等动词后的宾语从句中要用 “ (should) +动词原形” 来表示愿望,建议, 命令,要求等; 注意：由上述动词派生或转化的名词形式，如suggestion, proposal, plan, motion, recommendation, demand, order, desire, request, requirement, insistence, advice, decision , ）等的同位语从句或表语从句中也要用相应的虚拟形式.如：宾语从句如下表：He ordered （that） all the books (should) be sent at once.I propose that he (should) be chosen as the monitor(班长)The teacher demanded that all the students (should) hand in their notebooks after class.The doctor insisted/decided that he (should) not eat meat.表语从句及同位语从句如下表：His order was that all the books (should) be sent at once.(表语从句)He gave the order that all the books (should) be sent at once.(同位语从句)My propose was that he should be chosen as the monitor.(表语从句)The teachers demand was that all the students should hand in their notebooks after class.（表语从句）The doctors decision that he should not eat meat was reasonable(合理的).B) 在It is/was + 某些形容词 + that 从句的句型中,that从句中的谓语动词常用虚拟语气,即 “should + 动词原形” 。这些形容词有:important, necessary（必要的）, essential（关键的，及其重要的）, imperative（必需的）, natural, strange, advisable（可取的，明智的）, desirable（可取的）, possible, probable（很可能的）, astonishing（令人震惊的）, surprising, desired, suggested（被建议的）, requested,（被要求的） recommended（被推荐的）, ordered, proposed, decided, obligatory（义不容辞的, 必须的),moved（被提议的）等.如：It is necessary/essential/imperative/important that he should be given the chance.Its ordered that he should come back without delay.(他被命令不许回来迟了。)Its very essential that we should learn to speak English under the background of economic globalization.Its advisable that he should take part in the party.注意： should + 动词原形(或完成形式)” 可表示惊奇,遗憾,怀疑,不满等。I. 用于expect, believe, think, suspect 等动词的否定或疑问形式后的宾语从句中. 如： I never expected that the new apartment should be so small.II. 用于 “It is a pity, it is a shame, it is no wonder 等 + that” 等结构后的主语从句中. 如： It is a pity that he should be so careless.III.在由for fear that, in case, lest（以防）等引导的状语从句中,用 “ should + 动词原形” 表示 “惟恐，防备，推测”的意思.should可以省略。Eg. He handled the instrument with care for fear that it should be damaged.He walked out of the room quietly lest his mother should notice him.4） 用在wish之后的宾语从句中。表示现在的愿望，从句谓语用一般过去时，be换成wereI wish I were not at the party.我希望现在自己没在这个晚会上。表示过去的愿望，从句谓语用过去完成时或could have + V.edI wish I had studied harder last term.我希望上学期我学习更努力就好了。表示将来不大可能实现的愿望，从句谓语用would + V.I wish he would invite me to the party this weekend.5)用在It is about(high)time+ that从句中（表示应该做，但还没做）。That从句的谓语用一般过去时，that可省略。如：Its high time we went to bed. 6)在would rather, would sooner(宁愿), would just as soon(宁愿)的宾语从句中，从句谓语动词有两种情况：表示现在或将来虚拟时，谓语一般都用一般过去时；如：I would rather you came next week instead of today.表示过去虚拟用过去完成时。如；I would rather that I hadnt finished the task.7) 在 “as if/ as though” 引导的状语从句中,谓语动词与wish的宾语从句的虚拟形式相同.如： He works with such enthusiasm（热情） as if he never knew fatigue（疲劳）. He speaks English as though he were an American.注意：若as if从句表示的是真实情况，则不用虚拟语气，照常用陈述语气。如：It seems as if they know each other. (真实情况)It seems as though it were already spring. (虚拟语气)8） 用在if only （要是。就好了）引起的感叹句中.Eg. If o