1、语法点拨:if与unless引导的条件状语从句 1常用引导词:if(如果),unless(除非)。 I wont go to the movies unless I am free tomorrow. 除非我明天有空,否则我不会去看电影。 2条件状语从句的位置 可放在句首或句尾,放在句首时常用逗号与主句隔开。 e.g.If it rains tomorrow, I will stay at home. = I will stay at home if it rains tomorrow. 如果明天下雨我就呆在家里。 3if引导词用法 if引导的条件句有:真实条件句和非真实条件句两种。 真实条件
2、句:表示在某种条件下某事很可能发生。 e.g.If you ask him, he will help you.如果你请他帮忙,他会帮你的。 4unless引导词用法 固定搭配:unless=if.not 除非,若不,如果不 e.g.You will fail to arrive there in time unless you start earlier.=If you dont start earlier, you will fail to arrive there in time.如果你不早点动身,你就不能及时赶到那儿。 注意:在含有条件状语从句的复合句中,当主句是一般将来时态,从句要用
3、一般现在时(即主将从现原则)。如果主句是祈使句或含有情态动词时,从句也用一般现在时表将来。 e.g.If you study hard, you will pass the exam.1.Iwillsendyouane-mailassoonasI_A_inCanada.A.arriveB.arrivedC.amarrivingD.willarrive2.Ifthere_A_nobuyingandsellingofanimals,there_nokillinginnature.A.is;willbeB.willbe;willbeC.is;isD.willbe;is3.Imwaitingformy
4、friend._C_,Illgoshoppingalone.A.IfshecomesB.IfshewontcomeC.Ifshedoesntcome5.YoucantwatchTV_A_youfinishyourhomework.A.unlessB.ifC.whileD.as7.Thestudents_A_haveasportsmeetingthisweekendifit_.A.wont;rainsB.will;rainsC.wont;willrainD.aregoingto;isgoingtorain9.Idontknowifshe_B_tomybirthdaypartytomorrow.Ifshe_,Illbeveryhappy.A.comes;comesB.willcome;comesC.comes;willcome10.WhenwillyoucometoDaqing?Iwillcallyou_D_Iarrive.A.tillB.whileC.asquicklyasD.assoonas11.IllgiveittoJimassoonasI_C_himtomorrow.A.sawB.willseeC.seeD.haveseen