內 容 提 要
語氣是一種動詞形式，用以表示說話者的意圖或態度。虛擬語氣表示說話者的主觀愿望、假想和建議等，所說的話有的與現在事實相反，或與過去事實相反，或與將來事實相反或與將來事實可能相反。所以虛擬語氣總是與假設條件句用在一起。除了if條件句外，還有幾種常用的條件句，短語也可表示條件。此外，上下文也能創造虛擬的語言環境。但有時條件從句與結果主句可能發生時間不一致，有時虛擬語氣會出現倒裝情況。除了與條件句在一起使用的主句用虛擬語氣外，有些賓語從句或表語從句也有用虛擬語氣的情況。
I虛擬語氣的形式與基本用法
一、虛擬語氣的形式
虛擬(條件)語氣中，主句與從句中謂語動詞的形式可分為下面四類
假設類型
條件從句謂語
動詞形式
主語謂語
動詞形式
與現在事實相反
動詞的過去式(be用were而不用was)
would(第一人稱可用should)
+動詞原形
與過去事實相反
had+ -ED分詞
would(第一人稱可用should)
+have + -ED分詞
與將來事實相反
were to + 動詞原形
would(第一人稱可用should)
+動詞原形
與將來事實可能相反
should + 動詞原形
would(第一人稱可用should)
+動詞原形
二、虛擬語氣的基本用法
1. 與現在的事實相反
1) What type of automobile would you buy ?
[A] if you have free choice to choose the cars available today
[B] if you are free to choose among all the cars available today
[C] if all cars available were free to be chosen by you
[D] if you were free to choose among all the cars available today
2. 與過去的事實相反(有時主句中的should have done表示責備或后悔)
2) ，he would have come to class.
[A] If Mike is able to finish his homework
[B] Would Mike be able to finish his homework
[C] If Mike could finish his homework
[D] If Mike had been able to finish his homework
3) If the United States had not entered the Second World War，probably the 1940 unemployment rate of 14% still further.
[A] would rise
[B] would risen
[C] would have risen
[D] had risen
4) Top?grade [A] diamonds had not [B] increased so sharply [C] in value in the late seventies [D] if one company had not controlled almost all of the world’s supply.
3. 與將來的事實相反
5) The report would be [A] released last January if new developments had not [B] made it necessary to revise all conclusions drawn from [C] the first series of [D] experiments.
6) It is said Tom will go to an appointment tommorrow. If he were to come tomorrow, I ask him to go to your place.
[A] will
[B] would
[C] shall
[D] might
7) If you to see Mary，what would you tell her?
[A] are
[B] will be going
[C] must
[D] were
4. 與將來的事實可能相反
(1) If it should rain tomorrow, I would stay at home. 要是萬一 明天下雨，我就呆在家里不出去。 事實上 現在天氣很好，明天下雨的可能性應該不大，不過也說不準。
(2) If I should see her next Monday, I would tell her about it. 如果下周一我能見到她的話我就把這件事告訴她。
三、例題解析
1) D為正確答案。
2) D為正確答案。
3) C為正確答案。
4) B錯。改為would have not。
5) A錯。改為would have been。
6) B為正確答案。
7) D為正確答案。
II 虛擬語氣的特殊表現形式
一、表示“好像”：除了if條件從句外，由as if和as though等引導的狀語從句表示方式時，意思是“好像”,這時從句中的謂語動詞應用虛擬語氣。其動詞形式用過去時(be用were的形式)表示所說的與現在的事實相反;用過去完成時表示所說的與過去的事實相反
1) Violetta has a curious [A] expression on [B] her face as though she was smiling [C] about something that amused her [D] .
二、特殊連詞的需要：lest, for fear that和in case引起的從句(這時謂語多用should+加動詞原形)
We dare not play jokes on Mr. Wang lest he should become angry. (我們不敢跟王先生開玩笑，恐怕他生氣。)
He hurried on, lest he should drop out in the forced match. (他加緊步伐，生怕在急行軍中掉隊。)
Every attention must be paid to him lest he (should) feel that he is inferior to my other guests. (我對他特別關照，唯恐他感覺到比我的其他客人低人一等。)
He’s working hard for fear that he should fail in the exam. (他加緊學習唯恐考試不及格。)
