虛擬語氣是英語中一種重要的語氣形式，也是英語語法中一個重要的語法點。
由于虛擬語氣所涉及的內容比較廣，一些語法書對其的闡述也很繁雜，所以同學們在學習過程中很難掌握其用法，在使用過程中或考試時也很容易出錯。為了便于大家理解和記憶，筆者對虛擬語氣作了一個“新”歸納，供大家參考。
虛擬語氣的使用主要體現(xiàn)在三個方面：虛擬條件句、虛擬語氣在某些從句中的運用，以及虛擬語氣的一些特殊用法。
虛擬條件句
虛擬條件句就是對現(xiàn)實條件的一種虛擬假設，所假設的條件一般不符合事實或與事實相反或在現(xiàn)實中發(fā)生的可能性極小。根據(jù)時間的不同，虛擬條件句可分為三種，即與現(xiàn)在事實相反的虛擬條件句、與過去事實相反的虛擬條件句及與將來事實相反的虛擬條件句。具體情況請看下表：
例句：
1.表示與現(xiàn)在事實相反
If I had enough money now ， I would lend it to you.
If I were you ， I would go to tell him the real feeling upon him.
2.表示與過去事實相反
If he had taken your advice ， he wouldn’t have made such a bad mistake.
She would have come to enjoy the party if she hadn’t been very busy.
3.表示與將來事實相反
I would go shopping with you if it were to be Sunday tomorrow.
If he were to be given another chance to do it again， he could certainly achieve more.
1.虛擬條件句的倒裝
在虛擬條件句中，為了強調所假設條件的虛擬性，或突出說話人的一種主觀愿望，虛擬條件句可用倒裝結構。虛擬條件句的倒裝是通過去掉if，把條件從句謂語中的助動詞、情態(tài)動詞或系動詞放在句首實現(xiàn)的。例如：
Had I been（= If I had been ） in that situation， I would not have let the thief escape away with so much money.
Should there be （= If there should be） a drought， what should we do at that time ？
2.錯綜時間條件句
有時條件從句的動作和主句的動作發(fā)生的時間并不一致，這時謂語動詞的形式應根據(jù)它所要表示的具體時間來決定。例如：
If we hadn’t been working hard in the past few years ， things wouldn’t be going so smoothly.
If the Party hadn ’t led the Chinese people to liberate the country，Chinese people would still live a life in pain and poverty.
3.含蓄條件句
有時假設的情況并不以條件從句的形式表現(xiàn)出來，而是通過某個介詞或介詞短語（如：with， otherwise， without， but for， in that position ）、上下文或其它方式表現(xiàn)出來。這種句子稱為含蓄條件句。例如：
But for the help from you ， I would not have had the chance to go to college.
I would never mind you making such loud noises， but， you see， my baby is in a deep sleep.
It was so quiet ； you could have heard a pin drop.
虛擬語氣在某些從句中的運用
在某些詞或短語后接的從句中要使用虛擬語氣，表示愿望、建議或命令等。根據(jù)虛擬語氣的形式不同，虛擬語氣可以分為“should類”和“過去時態(tài)類”。
一、should類
這一類的虛擬語氣是通過從句中的謂語動詞使用“should +動詞原形”體現(xiàn)出來的，should可以省略。其具體運用體現(xiàn)在：
1.在suggest ， order， demand ， propose， command， request， desire，insist等表示建議、命令、要求、意見的動詞后接的賓語從句中要使用虛擬語氣。
如：
He suggests that she should leave the house at once.
The leader ordered that the task（should） be finished as soon as possible.
He proposed that we （should） deal with the problem by the view of development.
2.與suggest ， order， demand ， propose， command， request， desire，insist等動詞相對應的名詞suggestion， order， demand ， proposal 等后的表語從句或同位語從句中要使用虛擬語氣。如：
The general sent the order that the battle（should） be held on untilthe complete failure of the enemy.
My proposal is that we（should） set a deadline for handing in the plan.
3.在It is/was suggested （ordered ， demanded ， proposed ， etc. ） 結構以及necessary ， essential， important， strange， natural等形容詞后的主語從句中要使用虛擬語氣。如：
It’s requested that we （should） keep the stability of the society for the people’s peaceful life.
It is necessary that the badly wounded man（should） be treated immediately.
二、過去時態(tài)類
英語中，還有一些詞或短語后接的從句或句子，也要使用虛擬語氣，虛擬語氣是通過句中的謂語使用過去的某種時態(tài)（如：一般過去時、過去完成時等）來體現(xiàn)的。
1. wish ， would rather 后的賓語從句。如：
He wished he had never been involved in such affairs.
I would rather you could teach me again.
2. as if， as though引導的從句。如：
The little boy knows so many things as if he was a man.
He acted as usual as though nothing had happened.
3.由if only （要是……，那該多好?。。┮龑У捏@嘆句。如：
If only I had passed the test ！
If only it stopped raining！
4. It is（about/high） time 后的定語從句。如：
It is time we went out for a walk.
It was high time they had begun to prepare the experiment.
虛擬語氣的其它用法
在英語中，一些表示建議、請求、勸告、愿望、祈禱、祝?；蛟{咒的句子，也需要使用虛擬語氣。如：
Would you mind smoking here ？
May you be lucky！
Long live the people of China ！
God save me.
由于虛擬語氣所涉及的內容比較廣，一些語法書對其的闡述也很繁雜，所以同學們在學習過程中很難掌握其用法，在使用過程中或考試時也很容易出錯。為了便于大家理解和記憶，筆者對虛擬語氣作了一個“新”歸納，供大家參考。
虛擬語氣的使用主要體現(xiàn)在三個方面：虛擬條件句、虛擬語氣在某些從句中的運用，以及虛擬語氣的一些特殊用法。
虛擬條件句
虛擬條件句就是對現(xiàn)實條件的一種虛擬假設，所假設的條件一般不符合事實或與事實相反或在現(xiàn)實中發(fā)生的可能性極小。根據(jù)時間的不同，虛擬條件句可分為三種，即與現(xiàn)在事實相反的虛擬條件句、與過去事實相反的虛擬條件句及與將來事實相反的虛擬條件句。具體情況請看下表：
例句：
1.表示與現(xiàn)在事實相反
If I had enough money now ， I would lend it to you.
If I were you ， I would go to tell him the real feeling upon him.
2.表示與過去事實相反
If he had taken your advice ， he wouldn’t have made such a bad mistake.
She would have come to enjoy the party if she hadn’t been very busy.
3.表示與將來事實相反
I would go shopping with you if it were to be Sunday tomorrow.
If he were to be given another chance to do it again， he could certainly achieve more.
1.虛擬條件句的倒裝
在虛擬條件句中，為了強調所假設條件的虛擬性，或突出說話人的一種主觀愿望，虛擬條件句可用倒裝結構。虛擬條件句的倒裝是通過去掉if，把條件從句謂語中的助動詞、情態(tài)動詞或系動詞放在句首實現(xiàn)的。例如：
Had I been（= If I had been ） in that situation， I would not have let the thief escape away with so much money.
Should there be （= If there should be） a drought， what should we do at that time ？
2.錯綜時間條件句
有時條件從句的動作和主句的動作發(fā)生的時間并不一致，這時謂語動詞的形式應根據(jù)它所要表示的具體時間來決定。例如：
If we hadn’t been working hard in the past few years ， things wouldn’t be going so smoothly.
If the Party hadn ’t led the Chinese people to liberate the country，Chinese people would still live a life in pain and poverty.
3.含蓄條件句
有時假設的情況并不以條件從句的形式表現(xiàn)出來，而是通過某個介詞或介詞短語（如：with， otherwise， without， but for， in that position ）、上下文或其它方式表現(xiàn)出來。這種句子稱為含蓄條件句。例如：
But for the help from you ， I would not have had the chance to go to college.
I would never mind you making such loud noises， but， you see， my baby is in a deep sleep.
It was so quiet ； you could have heard a pin drop.
虛擬語氣在某些從句中的運用
在某些詞或短語后接的從句中要使用虛擬語氣，表示愿望、建議或命令等。根據(jù)虛擬語氣的形式不同，虛擬語氣可以分為“should類”和“過去時態(tài)類”。
一、should類
這一類的虛擬語氣是通過從句中的謂語動詞使用“should +動詞原形”體現(xiàn)出來的，should可以省略。其具體運用體現(xiàn)在：
1.在suggest ， order， demand ， propose， command， request， desire，insist等表示建議、命令、要求、意見的動詞后接的賓語從句中要使用虛擬語氣。
如：
He suggests that she should leave the house at once.
The leader ordered that the task（should） be finished as soon as possible.
He proposed that we （should） deal with the problem by the view of development.
2.與suggest ， order， demand ， propose， command， request， desire，insist等動詞相對應的名詞suggestion， order， demand ， proposal 等后的表語從句或同位語從句中要使用虛擬語氣。如：
The general sent the order that the battle（should） be held on untilthe complete failure of the enemy.
My proposal is that we（should） set a deadline for handing in the plan.
3.在It is/was suggested （ordered ， demanded ， proposed ， etc. ） 結構以及necessary ， essential， important， strange， natural等形容詞后的主語從句中要使用虛擬語氣。如：
It’s requested that we （should） keep the stability of the society for the people’s peaceful life.
It is necessary that the badly wounded man（should） be treated immediately.
二、過去時態(tài)類
英語中，還有一些詞或短語后接的從句或句子，也要使用虛擬語氣，虛擬語氣是通過句中的謂語使用過去的某種時態(tài)（如：一般過去時、過去完成時等）來體現(xiàn)的。
1. wish ， would rather 后的賓語從句。如：
He wished he had never been involved in such affairs.
I would rather you could teach me again.
2. as if， as though引導的從句。如：
The little boy knows so many things as if he was a man.
He acted as usual as though nothing had happened.
3.由if only （要是……，那該多好?。。┮龑У捏@嘆句。如：
If only I had passed the test ！
If only it stopped raining！
4. It is（about/high） time 后的定語從句。如：
It is time we went out for a walk.
It was high time they had begun to prepare the experiment.
虛擬語氣的其它用法
在英語中，一些表示建議、請求、勸告、愿望、祈禱、祝?；蛟{咒的句子，也需要使用虛擬語氣。如：
Would you mind smoking here ？
May you be lucky！
Long live the people of China ！
God save me.