自考“英語語法”基礎材料：虛擬語氣
時間：
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公共課
虛擬語氣
表示所說的不是事實，或者是不可能發生的情況，而只是一種愿望，假設或猜測。
1. 表示和現在事實相反的假設：
He is honest. If he were dishonest， I should not trust him. 他是誠實的。如果他不誠實的話，我就不會信任他。
He is not alive. If he were alive today， he would be a hero. 他死了。如果他今天活著的話，他會是個英雄。
If there were no air， there would be no living things. 如果沒有空氣，就沒有生物。
If there were no gravity， we should not be able to walk. 如果沒有引力，我們就不能行走。
In fact， I am not there. If I were there， I could solve the problem by myself. 事實上，我沒有在那里。如果我在那里的話，我自己就能解決這個問題。
2. 表示和過去事實相反的假設：
If there had been no air， there would have been no living things. 如果當初沒有空氣，也就沒有生物了。
You didn't come here yesterday. If you had come here yesterday， you would have seen him.
昨天你沒有來。如果昨天你到這里來了的話，你就看見他了。
If had not obeyed him， I might have been punished. 要是我那時不服從他的話，我可能受處分。
3.和將來事實相反的假設：
If he should be here tomorrow， he would call me up. 萬一他明天來這里的話，他會給我打電話的。（來的可能性很小）
If it were to rain tomorrow， the match would be cancelled. 萬一明天下雨的話，就將取消比賽。（下雨的可能性極小）
4.虛擬語氣的一些其他用法
（1）在動詞with， suggest， demand， insist 和order等后面的賓語從句中，一般用虛擬語氣（在用should+動詞原形時，should常可省略，而只用動詞原形，且用于所有的人稱）。例如：
I suggest that we （should） repair the machine at once. 我提議我們立刻修這臺機器。
The leader of the team ordered that all （should） finish the work by supper time. 隊長命令晚飯前都必須完成工作。
He insisted that all （should） attend the meeting. 他堅持大家都要參加那個會議。
（2）在“It is time（that） +從句”的結構中，從句的謂語動詞用過去式，表示“該做某事了，時間已經有些晚了”的意思。這也是一種虛擬語氣。例如：It is time we went to work. 我們該去工作了。
（3）在由as if， so that， in order that， as though等引導的狀語從句中，也往往用虛擬語氣形式。例如Annie treated me exactly as if I were a seeing and hearing child. 安妮對待我就好象我是一個能看能聽的孩子似的。
The Emperor gave the cheats some gold in order that they might begin their work at once. 皇帝給了騙子們一些金子以便他們能立刻開始工作。
（4）虛擬語氣在主語從句中的用法：在It is necessary （natural， strange， important） that等句型中，后面主語從句的謂語動詞要用“should+動詞原形”結構。例如：
It is strange that he should have been late for the meeting. 真奇怪，他開會遲到了。
It is necessary that we should take the box away at once. 我們有必要立即把這只箱子搬走。
表示所說的不是事實，或者是不可能發生的情況，而只是一種愿望，假設或猜測。
1. 表示和現在事實相反的假設：
He is honest. If he were dishonest， I should not trust him. 他是誠實的。如果他不誠實的話，我就不會信任他。
He is not alive. If he were alive today， he would be a hero. 他死了。如果他今天活著的話，他會是個英雄。
If there were no air， there would be no living things. 如果沒有空氣，就沒有生物。
If there were no gravity， we should not be able to walk. 如果沒有引力，我們就不能行走。
In fact， I am not there. If I were there， I could solve the problem by myself. 事實上，我沒有在那里。如果我在那里的話，我自己就能解決這個問題。
2. 表示和過去事實相反的假設：
If there had been no air， there would have been no living things. 如果當初沒有空氣，也就沒有生物了。
You didn't come here yesterday. If you had come here yesterday， you would have seen him.
昨天你沒有來。如果昨天你到這里來了的話，你就看見他了。
If had not obeyed him， I might have been punished. 要是我那時不服從他的話，我可能受處分。
3.和將來事實相反的假設：
| if從 句 | 主 句 |
| should+ 動詞原形 | should（would）+ 動詞原形 |
| were to+動詞原形 | |
| 動詞過去式 |
If it were to rain tomorrow， the match would be cancelled. 萬一明天下雨的話，就將取消比賽。（下雨的可能性極小）
4.虛擬語氣的一些其他用法
（1）在動詞with， suggest， demand， insist 和order等后面的賓語從句中，一般用虛擬語氣（在用should+動詞原形時，should常可省略，而只用動詞原形，且用于所有的人稱）。例如：
I suggest that we （should） repair the machine at once. 我提議我們立刻修這臺機器。
The leader of the team ordered that all （should） finish the work by supper time. 隊長命令晚飯前都必須完成工作。
He insisted that all （should） attend the meeting. 他堅持大家都要參加那個會議。
（2）在“It is time（that） +從句”的結構中，從句的謂語動詞用過去式，表示“該做某事了，時間已經有些晚了”的意思。這也是一種虛擬語氣。例如：It is time we went to work. 我們該去工作了。
（3）在由as if， so that， in order that， as though等引導的狀語從句中，也往往用虛擬語氣形式。例如Annie treated me exactly as if I were a seeing and hearing child. 安妮對待我就好象我是一個能看能聽的孩子似的。
The Emperor gave the cheats some gold in order that they might begin their work at once. 皇帝給了騙子們一些金子以便他們能立刻開始工作。
（4）虛擬語氣在主語從句中的用法：在It is necessary （natural， strange， important） that等句型中，后面主語從句的謂語動詞要用“should+動詞原形”結構。例如：
It is strange that he should have been late for the meeting. 真奇怪，他開會遲到了。
It is necessary that we should take the box away at once. 我們有必要立即把這只箱子搬走。