(精心整理)if和unless的用法讲解

Chapter1语法If和unless引导的条件状语从句我们用if引导的条件状语从句来讨论可能的条件以及该条件成立时可能的结果。一.学习if引导的条件状语从句的用法，我们可先从如下的 口诀 小学生乘法口诀表下载关于乘法口诀表的题目党史口诀下载一建市政口诀下载健身气功八段锦功法口诀下载 入手：If条件句不一般，几个要点记心间；条件句，放在前，逗号要句中间条件句 表 关于同志近三年现实表现材料材料类招标技术评分表图表与交易pdf视力表打印pdf用图表说话 pdf 可能，主句多用将来时；条件句表事实，主句常用现在时。Wecanwalkthereifwecan’tfindabus.如果我们找不到公车，也能走路去那里主句条件状语从句Ifitrainstomorrow,wewillnotgotothezoo.如果明天下雨，我们就不去动物园条件状语从句主句Whatwillyougoifyoufindsomeoneindanger?主句条件状语从句如果你发现某人有危险，你会怎么做？If条件句有不同的类型，简述如下：1.用if条件句表达客观真理或普通现象If条件句用于表达客观真理或普通现象时，主，从句时态均用一般现在时，如：Eg.Ifyoufreezewater,itturnsintoice.Afishdiesifyoutakeitoutofwater.2.用if条件句表示将来可能发生的事情在表示将来可能发生的事情的if条件句中，主句用一般将来时，而if从句用一般现在时表示将来的时间，即主将从现Eg.IfIlikethehouse,Iwillbuyit.如果我喜欢这房子，我就会把它买下IwilltellherifIseeher.如果我见到她，我就会告诉她。主句中的will也可以用情态动词can,may或might等代

替。如：Eg.Iftheyarefriendly，Imightinvitethemtotheparty.如果他们很友善，我可能会请他们去参加聚会Ifwehurrynow,wecanstopforcoffeelater.如果我们现在抓紧时间，就可以稍后去喝咖啡注意：在条件句中，主句部分只能使用动词will的一般将来时，不能使用begoingto的结构二.Unless的条件句表示在特定条件下，才决定做或不做一件事，中文用的连接词一般是“除非”和“否则”。如：除非刮台风，否则演唱会将如期进行。在英语中，我们可以用unless表达这个意思，相当于ifnot。以这个句子为例：Theconcertwillbeheldasscheduleunlessthereisatyphoon.=theconcertwillbeheldasscheduleifthereisnotatyphoonShewillkeeponsingingunlesssheistoldtostop.她会一直唱下去，除非有人叫她停止=shewillkeeponsingingifsheisnottoldtostop也可以用or(否则)来做同义句转换Unlessyoulistencarefully,youwon’tknowtheanswer.=ifyoudon’tlistencarefully,youwon’tknowtheanswer.=youshouldlistencarefully,oryouwon’tknowtheanswer.深圳中考题：1.If

I________hisphonenumber,Iwilltellyou.A.findB.foundC.willfindD.havefound2.Wewillgocampingifit_______tomorrow.A.Won’trainB.didn’trainC.doesn’trainD.isn’training3.I’mwaitingformyfriend.Ifhe_______,I______swimmingalone.A.doesn’tcome;willgoB.won’tcome;willgoC.willcome;won’tgoD.don’tcome;willgo4.______yougotothesupermarketat7p.m,youcanbuyalotofcheapfood.A.IfB.UnlessC.WhetherD.When5.Iwon’tgettothepartyontime______Icatchthefirsttraintomorrowmorning.A.IfB.UnlessC.WhetherD.When6.------Shallwegoonapicnicthisweekend?------Goodidea!Unlessit_______.A.rainsB.doesn’trainC.rainD.won’train7.-----CanIchangethejacketforanotherone______itdoesn’tfitmewell?-----Ofcourse.A.unl

essB.ifC.thatD.though8.Nobodycanlearnmathswellheworkshardonit.AifBunlessCthoughtDhowever9.Iffishawayfromwater,theydie.Aaretaking,won’tBaretaken,willCarebeingtaken,willDtake,won’t10.Eachstudentcanaskteachersforhelpifhehowtoworkouttheproblem.AwillknowBwon’tknowCdon’tknowDdoesn’tknow​一A用if或unless填空1.hewantstoseeme,youcantellhimtowait.2.itsnowstomorrow,we’llhaveadayortwooff.3.Wewon’tgotohispartyheinvitesus.4.Sheissuretopasstheexaminationsheisill.5.I’lltakethatcomputerIhaveenoughmoney.6.mygrandmawearsglasses,shecanseebetter.7.Iwon’tbuythatbackpackitcostslessthan$208.I’mtired;I’llhavearestfortea.9.Youwon’tgetpaidfortimeoffyouhaveadoctor’snote.10.youwillgetato

othacheyoudocleanyourteethregularly.B用所给单词的适当形式填空1.Ifhe(get)alowmarkinthetest,he(study)harder.2.Ifyou(swim)everydaythissummer,you(be)veryhealthy.3.Ifhe(nothurry),he(notsee)thebeginningofthematch.4.Youcan’tgooutunlessyou(finish)yourhomework.5.UnlessIsavemymoneycarefully,I(notbe)abletobuyafootball.6.Ifit(notrain)tomorrow,we(go)tothepark.7.Ifhe(return)totheschool,I(let)youknow.8.Hesmokingunlesshe(have)enoughmoney.9.Theycanrememberitbetterifsomeone(give)themsomeadviceaboutit.10.Theman(setoff)ifhe(buy)theairticket.二解释句子1.youwillfeelworseunlessyoutakemorerest.2.youwillbelateforworkifyoudon’thurryup.3.nooneisgoingtohelpyouunlessyouchangeyourmind.​PAGE/NUMPAGES