高中英語語法

—if引導(dǎo)的條件句由if引導(dǎo)的條件狀語從句表示在某種條件下某事很可能發(fā)生。1.Ifyouaskhim,hewillhelpyou.如果你請他幫忙，他會幫你的。2.Ifyoufailintheexam,youwilllethimdown.如果你考試不及格，你會讓他失望的if引導(dǎo)的條件狀語從句既可以將從句放前面也可以將從句放后面（如果天下雨，我們就不玩了）Ifitrains,wewillstopplaying.‘轉(zhuǎn)為Wewillstopplayingifitrains.if從句還表示不可實現(xiàn)的條件或根本不可能存在的條件（虛擬或假設(shè)）從句多用一般過去時或過去完成時。IfIwereyou,Iwouldinvitehimtotheparty.如果我是你，我會邀請他參加聚會。IwouldhavearrivedmuchearlierifIhadnotbeencaughtinthetraffic.如果沒有堵車，我會到的早一點兒。分級練習(xí)Areyouready?FIRSTSECONDTHIRDZEROIf

I

am

lateforschool,myteachergets

angry.IfclauseMainclauseIf+PresentsimplePresentsimpleIfIoversleep…Imissthebus.IfImissthebus,Iamlateforschool.IfIamlateforschool,myteachergetsangry.If

I

go

toLondon,Iwill

see

theBigBen.IfclauseMainclauseIf+Presenttensewill/can/may/must+verb

IfIgotoLondon…IwillseetheBigBen.IfIgotoBuckinghamPalace,IcantakeaphotooftheRoyalGuard.IfyougotoLondon,youmust

look

rightbeforecrossingastreetIfclauseMainclauseIf+PastSimplewould/could/might+verbIfIwereanastronaut,Iwouldtravelinaspaceship.IfIwereanastronaut,Iwouldtravel

inaspaceship.IfItravelledinaspaceship,Iwouldgo

toMars.Nicetomeetyou!IfIwenttoMars,Iwouldmeet

aMartian.IfImetaMartian,Iwouldn’tunderstand

him.?IfIavedIfIdidn’tunderstandhim,Iwouldcome

backtotheEarth.If

I

hadstudiedhard,Iwouldhavepassedmyexams.IfclauseMainclauseIf+PastPerfecttensewould/could/might+have+pastparticiple

IIfyouhadstudiedhard,youwouldn’thavefailedyourexam.IIfyouhadpassedyourexam,youc