初中英语If引导的条件状语从句.pdf

初中英语引导的条件状语从句 在 if 引导的条件状语从句中，if 和条件句位置灵活，可直接放在主句后面，若 if 条件句放句首，从句后面要加逗号，和主句隔开。还要注意前后时态一 致原则.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。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。三 如果 if 条件句谈论的是重复发生和预示要发生的情景和事件，则主从句大多用一般现在时态。如：If bears are in danger,they attack people.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 wifeto the party.-If your wife _,so will mine。.A.will go，goB.will go,goes C.goes,will goD.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。总结 引导的 一、表示将来可能发生的：主句一般将来时 从句一般现在时 主句为祈使句或情态动词形式 情态动词 二、表必然发生的 主句一般现在时，从句一般现在时（相当于 when 引导的从句）引导的 练习 1.He _(fail)in the exam if he _(not study)hard.2.Unless you _(leave)now,you _(be)late.3.We _(have)a barbecue unless it _(rain).4.Hurry up,or you will miss the bus.（同义句转换）_ you don t hurry up,you _ catch the early bus.5.Study hard,or youll miss fall behind（同义.句转换）_ you study hard,you_ fall behind.6.If you don t put on your scarf,you （ll 同 catch 义句 cold 转换.）Put on your scarf,_ you ll catch cold.7.I dont know if it_ tomorrow）.(表是否，用将来时态)If it _,I won t go shopping.（(rain)表如果，用现在时态）8.I want to know if he _(come)tomorrow,if he _(come),I _(give)the massage to him.9.Please let us know if he _(arrive)tomorrow.请告诉我们他明天 是否会来 Please let us know if he _(arrive)tomorrow.如果他明天来的话请告诉我们 10.I msure if he _(go)to the party,he_(have)a great time.11.If the rain _(stop)tonight,we will go to the cinema.12.I ll buy a computer if I _(have)enough money.13.You _(not get)nervous if you _(do)enough exercise.14.If she _(be)kind to me,I _(not argue)with her.15.If you _(pay)more attention to that,he _(not get)injured.16.Mr Li will be mad if we _(break)the rules.17.If it _(be)cloudy,they _(not go)there by air.18.Shall I say Hello when the foreigner _(come)intothe classroom?19.He ll get better grades if he _(study)hard.20.If you work really hard,you _(be)famous and rich.条件状语从句的时态练习 一在正确的答案下划一条线。1.Daina(will go/go/goes)to Europe if she(will pass/pass/passes)the exams.2.The graduates(will teach/teach/teaches)in the poor village if the Ministry of Education(will agree/agree/agrees)soon.3.If a UFO(will land/land/lands)in front of me,I(will go/go/goes)in to look for the alien.4.If he(will have/have/has)money,he(will bulid/build/builds)a science lab.5.Don t wait for me if I(am/will be)late.6.They(won t/don t)go to the beach if it(will rain/rain/rains).7.I(will call/call)you if he(will stay/stay/stays)at home.8.(Will/Do/Does)he visit the museum if he(won t/dontired?t/doesn t)get 9.Where(will/do/does)they live if they(will miss/miss/misses)the bus?二、用所给词的适当形式填空 1.If you _(feel)tired,you _(have)to have a rest.3.If there _(be)fewer trees,there _(be)more pollution.5.If Marcia _(live)alone,she _(keep)a pet parrot.6.Lana _(buy)a new dress if the old one _(be)out of style.7.The twins _(fight)if they_(argue).8.I _(have)a bake sale if I _(need)money for education.9.Peter _(send)me a beautiful souvenir if he _(tour)Spain.10.If Mr Green _(say)I am hard-working,my parents _(feel)glad.11.I _(go)to the beach if it_(not rain)this week.12._they _(have)a match if the P.E.teacher _(be)busy?13.He _(write)a letter to his grandparents if he _(get)his report card this week.14.If she _(get)up late,she _(not catch)the early bus.15.Peter _(major)in English if he _(pass)the exams in Peking University.单项选择（15 分）1.If you _ to the party,you ll have a great time.AB.wentillgo C.go D.going 2.It will be a long time _ Peter _ his work.A.since,has finished B.after,finishes C.when,will finish D.before,finishes.3.What will father _ us from Japan?A.take B.bring C.carry D.make 4.Weifang is famous _ kites.A.for B.to C.on D.with 5 I _ her the answer if she _me.A.can tell,will ask B.will tell,will ask C.would tell,askD.will tell,asks 6.What are you going to do tomorrow?-We ll go to the library tomorrow if it _.A.isn t rainB.rain C.won t rainD.doesn t rain 7.Do you know when he will come back tomorrow?-Sorry,I don t know.When he _ back,ell Iyou.ll t A.comes B.will come C.come D.may come 8.What will you do if you _ to the old folk s home visit?A.go B.went C.going D.will go 9.If I eat _ food,I ll be very fat.A.too many B.many too C.too much D.much too 10.I ll give the book to him if he _ here next Sunday.A.will come B.comes C.is coming D.came 1-5 CDBAD 6-10 DAACB 11-15