資源描述：
《Grammar and usage1》由會(huì)員上傳分享，免費(fèi)在線閱讀，更多相關(guān)內(nèi)容在行業(yè)資料-天天文庫(kù)。
1、GrammarandusageUnrealconditionals虛擬語(yǔ)氣中的非真實(shí)條件句虛擬語(yǔ)氣可用于條件句和其它一些從句中。虛擬語(yǔ)氣用于條件句中比較多,情況也比較復(fù)雜,所以要特別加以注意,首先要判斷一下是否應(yīng)該用虛擬語(yǔ)氣,因?yàn)闂l件句分為兩種,一種是真實(shí)條件句,一虛擬語(yǔ)氣的介紹:種是非真實(shí)條件句,只有在非真實(shí)條件句中才用虛擬語(yǔ)氣,在真實(shí)條件句中,要用陳述語(yǔ)氣。非真實(shí)條件句的時(shí)態(tài)表達(dá):如果假設(shè)的情況完全不存在或者實(shí)現(xiàn)的可能性很小,可以說(shuō)幾乎沒(méi)有時(shí),就需要用虛擬語(yǔ)氣來(lái)表達(dá),也就是說(shuō),這時(shí)的條件句是非真實(shí)的條件句。此時(shí)的句子時(shí)態(tài)比真實(shí)條件句中的時(shí)態(tài)后退一
2、步。虛擬語(yǔ)氣1.條件從句和主句中的虛擬語(yǔ)氣時(shí)間料從句主句與現(xiàn)在事實(shí)相反If+主語(yǔ)+動(dòng)詞的過(guò)去式(be-were)…主語(yǔ)+should/would/could/might+動(dòng)詞原形與過(guò)去事實(shí)相反If+主語(yǔ)+had+過(guò)去分詞主語(yǔ)+should/would/could/might+have+過(guò)去分詞與將來(lái)事實(shí)相反If+主語(yǔ)+wereto/(should)+動(dòng)詞原形主語(yǔ)+should/would/could/might+動(dòng)詞原形注:當(dāng)從句的if省略時(shí),句子要倒裝,如IfIwereyou,Iwouldnotdothat.WereIyou,Iwouldnotdo
3、that.注意:在ifI/he/she/it之后,可用were代替was。兩者在意義上沒(méi)有區(qū)別,但是were更為正式,特別是在稱述心存懷疑的事情時(shí):Ifshewereready,wewouldgo.在與將來(lái)事實(shí)相反的條件從句中,我們可以用wereto或should+do來(lái)表示,如:IfIweretofailmyEnglishtest,Iwouldhavetotakeitagainattheendoftheterm.注意:Ifheshouldcometomorrow,Iwouldtalktohimaboutit.PracticeReadthedialo
4、gueatpage40andfillineachblankwiththecorrectformoftheverbinbrackets.在非真實(shí)條件句中,如果有were,had,should,我們可以將if省略,把這些詞置于句首,采用倒裝形式,如:虛擬條件句中的省略與倒裝IfIshouldmeether,Iwouldtellher.=ShouldImeether,Iwouldtellher.IfIwereinyourposition,Iwoulddoitbetter.=WereIinyourposition,Iwoulddoitbetter.Ifthe
5、yhadmadepreparations,theywouldhavesucceeded.=Hadtheymadepreparations,theywouldhavesucceeded.有時(shí)非真實(shí)條件句中,主句謂語(yǔ)動(dòng)詞所表示的動(dòng)作和條件從句中謂語(yǔ)動(dòng)詞所表示的動(dòng)作并不同時(shí)發(fā)生,這時(shí)動(dòng)詞的形式并不完全按照上述表格來(lái)進(jìn)行,而需要按照各自的時(shí)間來(lái)調(diào)整,這樣的句子就叫錯(cuò)綜時(shí)間條件句。錯(cuò)綜時(shí)間條件句如:Ifyouhadfollowedthedoctor’sadvice,thenyouwouldbeallrightnow.IfIhadn’tfinishedmycom
6、positionbynow,Iwouldbeworkingonittomorrow.Ifshehadpreparedwellforherlessonsyesterday,shewouldn’thavesomanydifficultiesnow.有時(shí)一個(gè)假設(shè)的情況并不用條件從句表示,而用其它方式來(lái)表示,這樣的句子叫含蓄條件句。用with,without等介詞短語(yǔ)或分詞短語(yǔ)或者獨(dú)立主格結(jié)構(gòu)來(lái)代替條件從句。含蓄條件句Wemighthavediedwithoutyourhelp.=Wemighthavediedifyouhadn’thelpedus.Havi
7、ngknownintime,wecouldhavestoppedit.=Ifwehadknownintime,wecouldstoppedit.在條件從句中除最常見(jiàn)的連詞之外,尚有下列連詞:otherwise;incase;butthat;onconditionthat;unless;suppose/supposing(that);solongas;provided/providing(that)2.用相當(dāng)于if的其他連詞表示虛擬結(jié)構(gòu)Iwasbusylastweek,otherwiseIwouldhavecometoseeyou.Butthatyou
8、hadofferedhelp,theycouldn’thavefinishedtheirworkontime
