八年级条件状语从句讲练(附答案).doc

精品文档 引导条件状语从句的连接词主要有：if(如果）、unless（除非）或 as long as（只要）等。unless在意思上等于if.not。一、条件状语从句用法1、引导条件状语从句最常用的连词是if,由if引导的条件状语从句表示在某种条件下某事很可能发生。如: If you ask him, he will help you.如果你请他帮忙,他会帮你的。 If you fail in the exam, you will let him down.如果你考试不及格,你会让他失望的。 另外,if从句还表示不可实现的条件或根本不可能存在的条件,也就是一种虚拟的条件或假设,从句多用一般过去时或过去完成时。如: If I were you, I would invite him to the party.如果我是你,我会邀请他参加聚会。 2、unless = if.not. 除非,若不,除非在的时候例如：Lets go out for a walk unless you are too tired. =If you are not too tired, lets go out for a walk.Unless it rains, the game will be played.除非下雨,比赛将照常进行。3、so/as long as只要例句;You may borrow my book as long as you keep it clean. 只要你保持书的清 洁，你就可以把我的书借去。 So long as youre happy, it doesnt matter what you do. 只要你高兴，你做什么都没有关系。二、时态问题在条件状语从句中，要注意“主将从现”的规定，即主句用一般将来时，从句用一般现在时表示将来时。例句：I will come to see you if I have time. 我有时间，我就来看你。常见考法对于条件状语从句的考查，多以单选和完形填空的形式，从时态的角度设题，考查学生灵活运用的能力，或从连词的意义角度让大家选择连词。典型例题：If he _in half an hour,we _wait for him. A. wont come ,wont B.wont come ,dont C.doesnt come ,wont D.will come ,dont 解析：本题考查条件状语从句“主将从现”的运用。题干的意思是“如果他一小时后不来，我们将不会等他了”，从“in half an hour”，“一小时后”可知本句说的是未来的事，那么if引导的条件状语从句要用一般现在时表示将来时，主句要用一般将来时。答案：C误区提醒 if 既可以引导条件状语从句，表示“如果”，也可以引导宾语从句，表达“是否”。辨别它在这两种从句中的时态是我们经常容易出错的地方。另外，if 和unless的用法也需注意。 典型例题： -I wonder if your wife to the party. -If your wife _, so will mine。. A. will go， go B. will go, goes C.goes, will go D. will go, will go 解析：第一句中if表示“是否”，引导宾语从句，用将来时will go；第二句“如果你的妻子去，我的妻子也去”，if引导条件状语从句，用一般现在时表示将来时。 your wife，单三人称主语，所以用goes 。答案：B一、If引导的条件句*引导条件状语从句最常用的连词是if。if引导的条件句有真实条件句和非真实条件句两种（非真实条件句会在以后的虚拟语气中阐述），其引导的真实条件状语从句表示在某种条件下某事很可能发生。1、“if从句（一般现在时）+主句（一般现在时）”的条件句-表达真理或事实（动作必然发生）。 Ifyouheatice,itturnsintowater.如果你加热冰，它就会变成水。 Ifyouputsugerintowater,itdisappears.如果你把糖放进水里，它就会溶解。2、“if从句（一般现在时）+主句（一般将来时）”的条件句-谈论可能发生的事情。Ifitrainstomorrow,wellstayathome.如果明天下雨，我们会呆在家里。IfIdonthearfromhim,Iwontgo.如果没接到他的通知，我不会去。【注】这类条件句主句部分还可以用情态动词，如ImaybuyacarifIpassthedrivingtest.如果通过驾驶考试，我可能会买一辆车。Ifyougotoanothercountry,youmustobeythelocallaws.如果你去另一个国家，就必须遵守当地的法律。3、有时if引导的条件句可以与“祈使句，and/or”相互转换，Ifyoudonthurryup,youwillmissthebus.=Hurryup,oryouwillmissthebus.快点，否则你会错过这趟车。Ifyouuseyourhead,youllfindaway.=Useyourhead,andyouwillfindaway.动动脑子的话，你就会想出办法。二、unless引导的条件状语从句unless意为“除非、如果不”，用来引导否定意义的条件句，等于“ifnot”Letsgooutforawalkunlessyouaretootired.=Ifyouarenottootied,letsgooutforawalk.我们出去散步吧，除非是你太累。Unlessyoubrushyourteetheveryday,youwillgetatoothache.=Youwillgetatoothacheifyoudontbrushyourteetheveryday.如果不每天刷牙，你就会牙疼。用unless改写句子1.Ifyouhaventlistenedcarefully,youwontknowhowtodotheexamquestions.2.IfIdontleavenow,Iwillbelate.3.Wewillgetlostifwedonthaveamap.4.Ifyoudontreturnyourbooktothelibrarytoday,youwillbefined.5.Iwillbuythatdressifsomeonehasntboughtitalready.用if或unless填空1._hewantstoseeme,youcantellhimtowait.2. _itsnowstomorrow,wellhaveadayortwooff.3.Wewontgotohisparty_heinvitesus.4.Sheissuretopasstheexam_sheisill.5._Imtired,Illhavearestfortea.6.Iwontbuythatbackpack_itcostslessthan100yuan.7. Iwilllendyouthemoney_youpaybackontime.8. Youwillfailtheexam_youstudyhard.9.Iwillbuyacomputer_Iamabletosaveenoughmoney.10. _youdropaglass,itbreaks.单选1.IfI_hisphonenumber,Iwilltellyou.A.findB.foundC.willfindD.havefound2.Wewillgocampingifit_tomorrow.A.WontrainB.didntrainC.doesntrainD.isntraining3.Imwaitingformyfriend.Ifhe_,I_swimmingalone. A.doesntcome;willgoB.wontcome;willgo C.willcome;wontgoD.dontcome;willgo4._yougotothesupermarketat7p.m,youcanbuyalotofcheapfood.A.IfB.UnlessC.WhetherD.When5.Iwontgettothepartyontime_Icatchthefirsttraintomorrowmorning.A.IfB.UnlessC.WhetherD.When6.-Shallwegoonapicnicthisweekend?-Goodidea!Unlessit_.A.rainsB.doesntrainC.rainD.wontrain7.-CanIchangethejacketforanotherone_itdoesntfitmewell?-Ofcourse.A.unlessB.ifC.thatD.though8.-ifIgetgoodgradesthistime,myparents_metoHongKongforafive-daytrip.A.takeB.takesC.tookD.willtake9.If everyone _ the traffic rules, the roads will be much safer (安全得多). A. obey B. obeys C. obeies D. obeying10.We mustnt cross the road if the light _ red. A. turning B. are C. turns D. isI.单项选择1.If you _ to the party, youll have a great time. A. will go B. went C. go D. going2.It will be a long time _ peter _ his work. a. since, has finished b. after, finishesc. when, will finish d. before, finishes.3. what will father _ us from Japan? a. take b. bring c. carry d. make 5 I_ her the answer if she _me. a. can tell, will ask b. will tell, will ask c. would tell, ask d. will tell, asks6. what are you going to do tomorrow?-well go to the library tomorrow if it _. a. isnt rain b. rain c. wont rain d. doesnt rain7.Do you know when he will come back tomorrow?-sorry, I dont know. when he _ back, Ill tell you. a. comes b. will come c. come d. may come 8. what will you do if you _ to the old folks home visit?a. go b. went c. going d. will go9. If I eat _ food, Ill be very fat.a. too many b. many too c. too much d. much too10.Ill give the book to him if he _ here next sunday.a. will come b. comes c. is coming d. came11. There _an English film in our school tomorrow.a. is going to have b. will have c. is going to be d. has12.Could you tell us where _？a. will the next olympic games held b. the next o