虚拟语气
1 语气概述 在英语中，随着说话人对某一行为或事情的看法和 态度不同，谓语动词就用不同的形式，即称为语 气。英语语气有三种：陈述语气，祈使语气和虚 拟语气。 虚拟语气表示只存在于讲话人想象中的假设或推测， 而不是客观现实中的真实事件。它表示怀疑、忧 虑、推测、假设、想象或祝愿等，如
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I wish you were more careful. If I were not so busy, I would go and help him.
3. 虚拟语气在条件从句中和结果主句中的用法 （1）与现在事实相反时 1. I’m very busy now. If I had time, I would certainly go to the movies with you. 我很忙， 如果我有时间，我就当然会与你一起去看电影。（事实上我没 有时间，也不能与你一起看电影） 2. If I were you, I should go and see the dentist at once. 如果我是你，我就马上去看牙医。（事实上我不是你，也不会去看牙医） 3. If there were no gravity, we should not be able to walk. 如果没有引力，我们就不能走路。（事实上有引力，我们也能走路。）
2 虚拟语气在虚拟条件句与结果主句中的谓语动词 形式。 条件句中的 结果主句中的 谓语动词 谓语动词
与现在事实相反 动词过去式 ( be用were) had+过去分词
should/would could/might+动词原形 should/would/could might+have+过去分词
与过去事实相反 与将来事实可能 相反
（2）与过去事实相反 1. If you had come a few minutes earlier, you would have met her. 如果你早来几分钟，就会见到她了。（事实上没有早来，也 没有见到她） 2. If I hadn’t taken your advice, I would have made a big mistake. (3) 与将来事实可能相反 1. If it were Sunday tomorrow, I would go to see my friend there. 2. If I should do it, I would do it another way. 3. If I were to see him, I would speak to him about it. 4. I I dropped the glass, it would break.
动词过去式 should+动词原形 were+动词原形
should/would/could/ might+动词原形
注意：1主句中的should通常用于第一人称，would可用 于各种人称。根据意义上的需要可用情态动词could,might 代替should,would. 2 条件从句中如果谓语动词是be,其过去式所有人称 的单复数都用were,但在口语中，第一人称和第三人称单数 可用was代替were.但在if I were you中，必须用were,不 能用was代替。
7 虚拟语气的其它用法 （1）在主语从句中的用法 在这类句型里，that 所引导的主语从句的谓语动词，常用 should＋动词原形，should 可省去，但不换为would。 主句里谓语动词时态不限，这类句型常用一下三种形式：
A. It is /was +形容词+that…适用于这一句型的常用形容 词有： necessary, important, natural, strange, imperative, urgent, essential, probable, better, keen, possible, eager, anxious, unthinkable, astonishing等 It is necessary that the question (should) be settled at once. It seems incredible that he should have finished the work so soon. It was quite natural that he should think so.
5 混合虚拟条件句 如果虚拟条件句与结果主语的动作发生的时间不一致，主从 句的谓语动词就要根据各自动作发生的时间选用相应的虚 拟语气形式，如 If he had followed the doctor’s advice, he would be quite all right now. 他若当时听医生的话，他现在就痊愈了。 Had I taken my umbrella with me when I came out this morning, I should not be wet now. 如果我早上出来时带了伞， 现在就不会淋湿了。
4 省掉if 的条件从句结构 在书面语中，有时可不用连词if,而把were,had 或 should 移到主语前，形成没有if 的条件从句，其 意义不变。 If you had invited us, we should have come to your party. Had you invited us, we should have come to your party. Had you invited us, we would have come to your party.
6 含蓄虚拟条件句 有时虚拟语气不用条件从句，而是通过上下文或用介词短语 等表示出来，这种虚拟语气叫含蓄 虚拟条件句，如 The gifts to him would have filled a railroad freight car .(货车） I couldn’t have lived through Christmas without giving you a present. Bur for the leadership of the party, we would not live a happy life today. Man would die without air and water.