虚拟语气的用法小结.doc

虚拟语气的用法小结虚拟语气表示说话人的愿望、假设、猜测或建议，而不表示客观存在的事实。虚拟语气通过谓语的特殊形式来表示，下面对虚拟语气在各种句式中的用法分别介绍。一、虚拟语气在条件状语从句中的用法一）、表示与现在、过去和将来的事实相反，主句和从句的动词变化规则见下表：所述情况从句主句与现在事实相反If + 主语 + 动词过去式（be 动词用 were）主语 + wouldcouldmight should + 动词原形与过去事实相反If + 主语 + 动词过去完成式主语 + wouldcouldmight should + 动词现在完成式与将来事实相反If + 主语 + 动词过去式if + 主语 + were to + 动词原形If + 主语 + should + 动词原形主语 + wouldcouldmight should + 动词原形例如：If I were you, I would go at once. ( 与现在事实相反)If it should rainwere to rainrained tomorrow, we would not go camping. ( 与将来事实相反)If you had worked hard, you would have passed the exam. ( 与过去事实相反)If it were not for the rain, the crops wouldshould die. (与现在事实相反)注意：当条件状语从句表示的行为和主句表示的行为所发生的时间不一致时，被称为“错综时间条件句”，动词的形式要分别根据它所表示的不同时间作相应的调整。如：If you had followed my advice, you would be better now.二）、有时为了表达的需要，在虚拟语气中并不总是出现If引导的条件句，而通过其他手段来替代条件句，称为“含蓄条件句”。1、用介词短语代替条件句。常用介词有with, without, but for等。如：We couldnt have succeeded without your help (= If we hadnt got your help).But for the rain (= If it hadnt been for the rain), we would have finished the work.2、用不定式短语来代替条件句。如：It would be only partly right to do it in this way (= If we did it in this way.)3、用定语从句代替条件句。如：A nation which stopped working would be dead in a fortnight (= If a nation stopped working, it would be dead in a fortnight).4、用分词短语或独立主格结构来代替条件句。如：Having known in time (= If we had known in time), we could have stopped it.Everything taken into consideration (= If everything had been taken into consideration), they would have raised their output quickly.5、用一个副词或连词表示虚拟条件句。如：He telephoned to inform me of your birthday, or (= If he hadnt telephoned to inform me of your birthday) I would have known nothing about it.6、用相当与If的其他连词表示虚拟语气，在条件句中除了最常见的If连词外，尚有下列连词：otherwise否则，不然， in case假如, but that要不是, on condition (that)条件是, unless除非, supposing that假如, provided that如果I was busy last week, otherwise I would have come to see you.7、通过上下文来表示虚拟语气，这种情况要具体分析I would have given more money, but I was poor then. （前句虚拟语气，后句陈述语气）I would have called you, but I forgot your telephone number (= if I had known your telephone number. But I forgot it).三）、如果虚拟条件句中含有were, should或had，则可以把were, should或had提至句首，构成倒装句。如：Were I you, I would go at once.Should it rain tomorrow, we would not go camping.Had you worked hard, you would have passed the exam. 二、用“should + 动词原形”构成的虚拟语气，其中should可以省略。一）、suggest, advise, demand, require, request, desire, order, command, insist等动词之后的宾语从句中。The teacher suggested that we (should) not lose heart.The general ordered that the work (should) be finished at once.注意：当suggest作“暗示，表明”讲，insist作“坚持”说，即坚持事实是怎样时，后边that从句不用虚拟语气。如：Mike insisted that he had never stolen anything.The look on his face suggested that he was angry.二）、advice, suggestion, demand, requirement, requirement, request, desire, order, insistence等相关的表语从句、同位语从句中。如：My suggestion is that you (should) try another means. (表语从句)Order came that the army (should) reach next town before dark. (同位语从句)三）、在It is requiredsuggestedinsistedordered + that引导的主语从句中。如：It is required that all the students (should) go to school on foot. (主语从句)四）、在It is 形容词(necessary, natural, strange, ect.) + that引导的主语从句中。如：Its necessaryimportantnatural that we (should) clean the room every day.It was essential that the application forms (should) be sent back before the deadline.五）、在It iswas a pity (a shame, no wonder, etc.) + that引导的主语从句中。如：It was a pity a shame no wonder that our team should lose the game.当然在四）、五）两类的that从句中也可以不用虚拟语气，而用陈述语气。如：It is strange that he did not come yesterday.It is a pity that you cant dance.三、It is (highabout) time (that)后的定语从句中，常用动词的过去式，或should + 动词原形。此句型表示“现在该”，用来表示提议。如：It is high time (that) we started out.It is about time (that) we began should begin our discussion.四、用动词的过去式表示与现在事实或将来事实相反，用动词的过去完成式表示与过去事实相反的句型。一）、wish后that引导的宾语从句中。如：I wish I were as clever as you. ( 表示与现在事实相反)I wish he would try again. (表示与将来事实相反)二）、as ifthough引导的表语从句或方式状语从句中。如：He looks as ifthough he were an artist.He talks as if he had really been to the heaven.注意：在这种从句中，如果假设的情况很可能会发生，则可以不用虚拟语气。如：He looks as if hes angry with himIt looks as if its going to rain.三）、would rather后的宾语从句中。如：Id rather you didnt go there.Hed rather his father had been at his party last night.四）、if only引导的感叹句中。如：If only I were a bird. 我要是只鸟就好了。If only I had worked hard at English.五、用动词原形表示的虚拟语气一）、表示祝愿的句子。May you be happy! 祝你幸福！Long live the Peoples Republic of China. 中华人民共和国万岁！二）、表示让步的状语从句中。Come what may. Ill stick to my plan.六、虚拟语气表示委婉语气的句型，情态动词的过去式如could, would, might表示现在时间时，表示说话人的某种态度：谦虚、客气、委婉、不肯定等。如：It would be better for you not to stay up too late.Would you be kind enough to show me the way?4