一、虛擬語氣的基本形式和用法：

　　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三類：

　　1、I would ask George to lend us the money if I _____ him.

　　A. had known　 　B. have known

　　C. knew 　 　D. know

　　(答案：C.與現(xiàn)在的事實相反，從句用過去時)(1995年38題)

　　2、Do you think there would be less conflict in the world if all people _____ the same language?

　　A. spoke　 　B. speak

　　C. had spoken　 　D. will speak

　　(答案：A.與現(xiàn)在的事實相反，從句的謂語動詞用過去時。)

　　3、If Bob____ with us， he would have had a good time.

　　A. would come　 　B. would have come

　　C. had come　 　D. came

　　(答案為C.與過去的事實相反，從句的謂語動詞用過去完成時。)(1995年59題)

　　二、if的省略形式

　　在虛擬條件句中， 如謂語包含were ， had， should等詞， 則可以把這些詞放到主語前面，省略if.

　　1、_____ you were busy， I wouldn't have bothered you with my questions.

　　A. If I realized　　 B. Had I realized

　　C. Did I have realized that 　D. As I realized

　　(答案：B.虛擬條件句有時可以省略if，而將謂語中的過去式were，had，或should等移至主語之前。)(1996年39題)

　　2、_____， I should ask them some questions.

　　A. Should they come to us　 　B. If they come to us

　　C. Were they come to us　 D. Had they come to us

　　(答案：A.與將來事實相反。)(1997年30題)

　　三、含蓄條件句

　　有時一個假設的情況不用條件從句表示，而用其它方式來表示，這樣的句子叫含蓄條件句。常用with，without，but for.

　　1、Without your help， we _____ so much.

　　A. didn't achieve 　　B. would not have achieved

　　C. will not achieve　 　D. don't achieve

　　(答案：B.這是一句含蓄條件句，條件暗含在介詞短語without your help中，因此要用虛擬語氣。)(1996年33題)

　　2、But for the rain， we _____ a nice holiday.

　　A. should have　 　B. would have had

　　C. would have　 　D. will have had

　　(答案：B.2003年28題)

　　四、以wish(that)引導的表示"愿望"的賓語從句

　　wish后的賓語從句中要用虛擬語氣，而在虛擬語氣中時態(tài)的應用類似在非真實條件中從句時態(tài)的應用。表示現(xiàn)在或將來的愿望用：主語+wish +從句(主語+過去時);表示一個過去沒有實現(xiàn)的愿望用：主語+wish +從句(主語+過去完成時);

　　1、Peter wishes that he _____ law instead of literature when he was in college.

　　A. could study　 　B. studied

　　C. had studied　 　D. would study

　　(答案：C)(2000年53題)

　　2、I didn't go to the party， but I do wish I _____ there.

　　A. were　 　B. would be

　　C. had been　　D. will be

　　(答案：C)(2001年53題)

　　五、would rather+句子(過去時)

　　1、I'd _____ you didn't touch that， if you don't mind.

　　A. rather 　　 B. better

　　C. happier　　 D. further

　　(答為案：A)(1998年45題)

　　2、I am too busy these days. I would rather all of you _____ next month for a dinner.

　　A. come　 　B. would come

　　C. came　　 D. have come

　　(答案為C)(2002年46題)