《綜合英語(yǔ)》課件-IF條件句精講

IF條件句if引導(dǎo)的條件句if引導(dǎo)的條件句表示在某種條件下，會(huì)導(dǎo)致另一事發(fā)生。句式為if從句+主句。中文意思是“如果某事發(fā)生（或不發(fā)生），另一事就（不）發(fā)生”。通常分以下兩種情形：一、真實(shí)條件句二、虛擬條件句一、真實(shí)條件句if從句用一般現(xiàn)在時(shí)，主句用一般將來(lái)時(shí)，表示從句中的動(dòng)作如果發(fā)生，那么主句中的動(dòng)作也將發(fā)生。如：

Ifitstopsraininglaterthisafternoon,wewilleatout.2.if從句和主句都用一般現(xiàn)在時(shí)，表示客觀真理或習(xí)慣和持續(xù)發(fā)生的事情。如：

Ifthemoongoesneartheearth,thetidegoeshigh.3.if從句用一般現(xiàn)在時(shí)，主句用祈使句，表示給某人提建議或命令某人做某事，及提出建議或請(qǐng)求。如：

Ifyouarenotlikelytobeintown,pleaseletmeknow.

二、虛擬條件句虛擬條件句，也稱非真實(shí)條件句，表示在某種假想的條件下，將導(dǎo)致某事發(fā)生。從句中所陳述的事情僅僅只是說(shuō)話者的想法，不是事實(shí)，也不可能發(fā)生。

虛擬語(yǔ)氣是一種特殊的動(dòng)詞形式，表示所說(shuō)的話不是一個(gè)事實(shí)，而只是一種假設(shè)，愿望，建議，懷疑，猜測(cè)或不大可能實(shí)現(xiàn)的空想。IfIhavetime,Iwillgowiththem.(陳述語(yǔ)氣)IfIwereyou,Iwouldgowiththem.(虛擬語(yǔ)氣)I.虛擬語(yǔ)氣用在條件狀語(yǔ)從句中虛擬語(yǔ)氣用在條件狀語(yǔ)從句中，通常從句由連詞if引導(dǎo)。1.與現(xiàn)在事實(shí)相反的虛擬條件句

IfIfeareddeath,Iwouldn’tbeaPartymember.怕死就不做共產(chǎn)黨員。Iftherewerenoair,wecouldn’tlive.如果沒(méi)有空氣，我們就不能生活。條件狀語(yǔ)從句主句If+主語(yǔ)+動(dòng)詞過(guò)去式(be的過(guò)去式用were)主語(yǔ)+would,should,could,might+動(dòng)詞原形

1.IwouldaskGeorgetolendusthemoneyifI______him.A.hadknown

B.knew

C.haveknown

D.know2.I_____ittohimifIthoughthewouldunderstand.shallexplain

B.willexplain

C.wouldexplain

D.explain2.與將來(lái)事實(shí)相反的虛擬條件句構(gòu)成

Ifheweretocometomorrow,thingswouldbeeasier.假如他明天會(huì)來(lái)，事情就容易辦了。條件狀語(yǔ)從句主句If+主語(yǔ)+wereto/should+動(dòng)詞原形If+主語(yǔ)+動(dòng)詞過(guò)去式(be的過(guò)去式用were)主語(yǔ)+would,should,could,might+動(dòng)詞原形Ifthesea____torise50feet,Indiawouldbecomeanisland.A.will

B.is

C.was

D.wereIfyou____seeMary,whatwouldyoutellher?A.are

B.willbegoing

C.must

D.should3.與過(guò)去事實(shí)相反的虛擬條件句構(gòu)成例如Iftherehadbeennoairinthetube,theresultwouldhavebeenbetter.條件狀語(yǔ)從句主句If+主語(yǔ)+動(dòng)詞過(guò)去完成式主語(yǔ)+would,should,could,might+have+過(guò)去分詞Ifyouhadn’tgonewithTomtothepartylastnight,_______.A.youwouldmeetJohnalready

B.youwon’thavemissedJohnC.youwillhavemetJohn

D.youwouldhavemetJohn4.省略連詞if在條件狀語(yǔ)從句中，如果有were,should,had，可以把連詞if省去，把were,should,had放在句首，構(gòu)成條件意義。例如：Ifitshouldraintomorrow,whatwouldyoudo?Shoulditraintomorrow,whatwouldyoudo?Ifwehadknownaboutthenewmethod,weshouldhaveapplieditearlier.Hadweknownaboutthenewmethod,weshouldhaveapplieditearlier.HadAlicebeenmorehardworking,she_______.A.hadnotfailed

B.wouldnotfailC.couldnotbefailed

D.wouldnothavefailed_______today,hewouldgettherebyFriday.A.Wouldheleave

B.WasheleavingC.Werehetoleave

D.Ifheleaves______difficulties,wewouldbesuccessful.A.Shouldweovercome

B.WouldweovercomeC.Mightweovercome

D.Couldweovercome5.虛擬結(jié)構(gòu)中省略主句或從句虛擬結(jié)構(gòu)中有時(shí)可省去主句或從句，并不影響意義的完整。(1)省去條件從句Thatwouldbefine.那太好了。（省去了ifyouwouldco