1、專題8情態動詞和虛擬語氣(二四、虛擬語氣用于條件狀語從句中(1表示與現在事實相反的假設,條件狀語從句中的謂語動詞用“過去式(be動詞的過去式用were”,而主句中的謂語動詞用“would / should/ could / might + 動詞原形”。如:If I were a boy, I would join the army.(2表示與過去的事實相反,條件狀語從句中的謂語動詞用過去完成時,主句中的謂語動詞則用“would / should / might / could + have +過去分詞”。如:If he had taken my advice, he would have su

2、cceeded in the competition.(3表示與將來事實相反,條件狀語從句中的謂語動詞一般過去時或should(were to + 動詞原形,而主句中的謂語動詞則用would / should/could might + 動詞原形。如;If it were to rain tomorrow, the football match would be put off.(4當條件狀語從句表示的行為和主句表示的行為所發生的時間不一致時,動詞的形式要根據它所表示的時間作相應調整。如:If they had worked hard, they would be very tired.(從句

3、說的是過去,主句指的是現在注意:有時侯在使用時可省略if,句子則可換成下列形式,即“were / had / should +主語”。如: Were I a boy, I would join the army.Had he taken my advice, he would have succeeded.五、虛擬語氣用于名詞性從句(1虛擬語氣在賓語從句中的運用。“wish + 賓語從句”表示不能實現的愿望,譯為“要是就好了”等。表示現在不能實現的愿望,從句中的謂語動詞用一般過去時;表示將來不能實現的愿望,從句中的謂語動詞用“would/could + 動詞原形”;表示過去不能實現的愿望,從句

4、中的謂語動詞用“had + 過去分詞”或“could(should + have + 過去分詞”。如:I wish it were spring all the year round.I wish I had known the answer.在表示建議、要求、命令等的動詞suggest、advise、propose、demand、require、insist request、command、order等后的賓語從句中,謂語動詞用should + 動詞原形或是動詞原形。如: She suggested we (shouldleave here at once.(2虛擬語氣在同位語從句和表語從句

5、中的運用。作表示建議、要求、命令等的名詞advise、idea、order、demand、plan、proposal、suggestion、request等的表語從句和同位語從句,從句中的謂語動詞用“(should+ 動詞原形”。如: His suggestion that we (shouldgo to Shanghai is wonderful.My idea is that they (shouldpay 100 dollars.(3虛擬語氣在主語從句中的運用。在主語從句中,謂語動詞的虛擬語氣用“should + 動詞原形”的結構,表示驚奇、不相信、理應如此等。如:It is neces

6、sary(important, natural, strange, etc.that we should clean the room every day.It was a pity (a shame, no wonder, etc.that you should be so careless.注意:這種從句表示的是事實。如果說人對這種事實表現出驚奇的情感,就可用虛擬語氣。反之,如果不表示驚奇等情感,that從句也可用陳述句語氣。如:It is pity that you cant swim.六、虛擬語氣在其他場合的運用(1虛擬語氣在as if/as though、even if/even t

7、hough等引導的表語從句或狀語從句中,如果從句表示的動作發生在過去,用過去完成時;指現在狀況,則用一般過去時;指將來狀況則用過去將來時。如:He did it as if he were an expert.(2虛擬語氣用于定語從句中。這種從句常用于句型“It is (hightime (that ”中,定語從句的謂語動詞用一般過去時(be 用were或should + 動詞原形,意思是“(現在該”。如:Its time that I picked up my daughter.(3虛擬語氣用在if only引導的感嘆句中。如:If only I had taken his advice.1

8、.Everyone in my class passed the exam.Oh,really?It _ difficult.(can't have been /needn't have been/must be /mightn't be【解析】can't have been 表示否定的推測應使用cant /cannot。對過去進行推測,表示“一定不”應使用cant have done。2.Some people who don't like to talk much are not necessarily shy;they _ just be quie

9、t people. (must /may/should /would【解析】may 句意為:有些人不喜歡講話不一定是害羞,他們可能是安靜的人。此處用may表示“可能”之意。3.Why didn't you answer the phone last night? I _ (sleepwhen you called.【解析】must have been sleeping 由時間狀語和結合語境來看,這是對過去某個時間點正在發生事情的肯定推測,再結合題意,應該是must have been doing結構。4.When I lived with my roommates in the uni

10、versity, we _ often talk into the night.(might/must/should/would【解析】would 這里描述的是過去經常發生的動作(或過去經常做的事情。5.This is the first time I _ (takemy first picture with my own hands. It is time that you _ a picture for me.【解析】have taken This/It is the first time that中,從句的謂語動詞通常用現在完成式;6.Why hasn't Jack come b

11、ack yet?Can anything have happened to him?I'm not sure, but I guess something _(have.【解析】may have 推測發生過的事情時情態動詞后要接完成式。7.Liza_ well not want to go on the trip she hates traveling.(will/can/must /may【解析】may .may well (not do sth.意為“很可能(不干某事,完全(沒有可能干某事”。8.The soccer team has been doing well this se

12、ason,so they _ win the championship.(should/might/would/must【解析】should句意為:這個足球隊在這個季度訓練得很好,因此,他們應該會贏得冠軍。根據常理進行推測表示“應該”時用should。9.What does the sign over there read? No person _ smoke or carry a lighted cigarette in this area.(will /shall /may /must【解析】shall. 答句句意為:任何人在這里都不能吸煙或者是攜帶點燃的香煙。Shall在這里表示強制,用

13、于法令、條約、規章中,意為“必須,應該”。10.For environmental reasons,we _ as well take these waste products and have themrecycled.(should/would/might /could【解析】might. 所填詞與as well構成固定搭配,意思是“不妨,還是為好”用may/might.11.We _ (behere at lunch time; we were delayed at the airport, though.【解析】would have been .would have done sth.

14、表示與已經發生的事實相反,意思是“本來會但實際沒有”。句意為:我們本來能在午餐時到達,但我們在機場被延誤了。12.You _ buy a gift,but you can if you want to.(must /mustn't/have to/don't have to【解析】don't have to。dont have to意為“沒有必要”,符合語境。句意為:你沒有必要買禮物,但如果你想買的話,你也可以買。13. May I take this book out of the reading room?No,you_. You read it in here.(

15、mightn't /won't /needn't /mustn't【解析】mustn't 本題考查情態動詞的用法。表示“禁止;千萬別做某事”時,要用mustn't。14I havent got the reference book yet,but I'll have a test on the subject next month.Dont worry. You _have it by Friday.(could /shall/must /may【解析】shall當主語為第二、三人稱時,情態動詞shall表示說話人給對方命令、警告、允諾或

16、威脅,本句表示允諾。15.George is going to talk about the geography of his country,but I'd rather he _ (focusmore on its culture.【解析】focused 。would rather+從句,從句表示對現在或將來虛擬時應使用一般過去時。16.Just be patient. You _ expect the world to change so soon.(can't /needn't/may not /will not【解析】can't 句意:耐心一點兒, 你

17、不能期望世界變化如此快。通過選項此題考查情態動詞, cant在否定句中可以表示推測, 譯為不可能,可以表示能力, 譯為不能夠,語氣強烈。也可以表示命令, 不允許, 但是語氣比mustnt弱, 具有勸慰的意思, 根據句意此題中選擇A, cant表示勸慰。17.Teachers recommend parents _ (not allow their children under 12 to ride bicycles to school for safety.【解析】not allow 。句意為:教師們建議:為了孩子們的安全,父母不應讓12歲以下的孩子騎自行車去學校。recommend意為“建議

18、”,其后接的賓語從句采用虛擬語氣,從句謂語動詞用“should+動詞原形”的形式,should可以省略。18.Mark _ have hurried. After driving at top speed,he arrived half an hour early.(needn't /wouldn't/mustn't /couldn't【解析】needn't.needn't have done 本沒有必要做某事,實際上做了。句意:邁克本來不必要那么忙的。這么高速駕駛之后, 他早半個小時到達了。根據后面的語境, 提前半個小時到達, 說明Mark本來不必那么匆忙, 所以用neednt have done 結構, 表示“本來不必要做某事的而實際上做了”。19.I _ have watched that movie it'll give me horrible dreams.(shouldn't /needn't /couldn't /mustn't【解析】shouldn't shouldn't have done意為“本不應該做但實際已經做了(表達后悔的