Unit1语法专项课件 if because状语从句

教学课件外研英语九年级上册Unit1语法专项——if&because状语从句

全解精讲+分层练习1.分清because原因状语从句、if条件状语从句用法2.掌握because两大句式与时态统一规则3.牢记if从句核心考点：主将从现4.区分because与so、because和becauseof的区别学习目标语法导入——状语从句概念

状语从句：用完整句子修饰主句，表原因、条件等

本节课两类从句：原因、条件状语从句

because引导原因，解释事情发生的缘由

if引导条件，描述假设带来的未来结果because引导原因状语从句・含义because意为“因为”，从句说明原因，主句表结果语序一：主句在前+because+从句

例句：Ilikepaper-cuttingbecauseit’sChineseart.语序二：Because从句放句首，加逗号再接主句

例句：Becauseit’straditional,weshouldprotectit.because从句时态规则主从句时态必须保持一致，无特殊变化一般现在时：描述常态、客观事实

Helearnspuppetrybecausehelovesfolkculture.一般过去时：描述过去发生的事

Shestayedhomebecauseshewasbusyyesterday.because核心禁忌1：不能和so连用because表原因，so表结果，二者二选一，不可同句

错误：Becauseartsaredying,soweprotectthem.

正确1：Artsaredying,soweprotectthem.

正确2：Weprotectartsbecausetheyaredying.because核心禁忌2：回答why只用becausewhy用来提问原因，答句必须使用because

—Whydoyoujointheartclub?

—IjoinitbecauseIwanttolearnshadowpuppets.

不能用if、so回答why问句易混辨析：becausevsbecauseofbecause+完整句子（主谓齐全）becauseof+名词、名词短语、动名词

例句1：Ilovepuppetsbecausetheyarebeautiful.

例句2：Ilovepuppetsbecauseoftheirbeauty.if引导条件状语从句・基础含义

if翻译为“如果”，提出假设条件

满足从句条件，主句就会出现对应结果

两大基础语序，逗号使用有区分

核心黄金规则：主将从现（重中之重）主将从现讲解if从句（条件）：一律用一般现在时主句（结果）：用一般将来时will+动词原形结构1：If+现在时，主句将来时（加逗号）

Ifyoupractice,youwillcutnicepaperworks.结构2：主句将来时if+现在时（无逗号）if从句主语三单变形规则从句主语是he/she/it/单数名词，动词变三单

Ifhelearnspuppetry,hewillspreadthisart.

learn→learns，末尾加s

对比：Iftheylearnpuppetry,theywillspreadit.if引导否定条件句从句否定：主语+don’t/doesn’t+动词原形

Ifwedon’tprotectarts,wewilllosethem.主句否定：willnot=won’t+动词原形

Ifshedoesn’tjointheclub,shewon’tlearncutting.if一词两种含义拓展区分条件状语从句：if=如果，遵循主将从现宾语从句：if=是否，时态跟随主句变化

例句1（条件）：Ifyoucome,Iwillshowpuppets.

例句2（宾语）：Idon’tknowifhewillcome.because与if从句对比表格引导词作用时态规则标志性考点because说明原因主从句时态统一不与

so连用，回答whyif提出假设条件主将从现从句用一般现在时解题步骤1选词填空判断逻辑1.先判断前后句逻辑：因果用because2.前后为假设条件关系，选用if3.句首If首字母必须大写4.因果句可提取关键词why、busy、reason5.条件句可提取will、soon、next等将来标志解题步骤2两句合并为because复合句1.找出表结果的句子作主句，表原因作从句2.主句在前直接加because连接从句3.从句放句首，末尾加逗号隔开主句4.统一主从句时态，不能出现时态冲突5.不可同时添加so，删掉多余连词解题步骤3两句合并为if条件句1.找出表假设的句子作if从句2.从句改为一般现在时，去掉will3.结果句作主句，保留will+动词原形4.从句前置加逗号，后置不用逗号5.注意三单、否定don’t/doesn’t变形易错点1主将从现时态颠倒

错误：Ifyouwillpractice,youmakegoodworks.

错误原因：从句不能使用将来时will

改正：Ifyoupractice,youwillmakegoodworks.

口诀：if从句永远现，主句将来will现易错点2because与so叠加使用

错误：BecauseIlikeart,soIjointheclub.

修正方案二选一：删because或删so

正确：Ilikeart,soIjointheclub.

正确：IjointheclubbecauseIlikeart.易错点3becauseof后接完整句子1.错误：Iloveartbecauseofithaslonghistory.2.becauseof后只能接名词短语，不能接句子3.改正：Iloveartbecauseithaslonghistory.4.有主谓完整句子，统一用because易错点4过去时态不统一1.错误：Hemissedtheshowbecauseheisbusy.2.主句didn’t为过去式，从句同步用was3.改正：Hemissedtheshowbecausehewasbusy.4.看到过去时间词，前后时态全部变过去题型一if/because选词填空

1.Wesavepaper-cutting__________itispreciousculture.2._______wekeeppracticing,wewillmasterpuppetry.3.Sherecordspuppetshows_______shewantstosharethem.4._______youignoreoldarts,theywilldisappearslowly.5.Ididn’ttakepartintheactivity_______Iwasill.becauseIfbecauseIfbecause6.Folkartsattractteenagers_______theyarefullofbeauty.7.Thepuppetlooksvivid_______youcontrolitskillfully.8.Manyelderslovepaper-cutting_______theygrewupwithit.9._______morestudentslearntraditionalskills,theywon’tdisappear.10.Werespectfolkartists_______theycarryonoldculture.becauseifbecauseIfbecause题型二单项选择题

1.—Whydoyoulearnshadowpuppets?—_______theycarrythousandsofyearsofhistory.A.IfB.BecauseC.So2.Ifyou_______hard,you_______makeperfectpaper-cuts.A.work;willB.willwork;doC.work;do3.Weshouldprotectoldcrafts,_______theyaredisappearing.A.ifB.becauseC.so4._______yourefusetolearnfolkarts,you_______losetraditionalknowledge.A.If;won’tB.If;willC.Because;will5.Becauseshelovesculture,_______shelearnspuppetry.A.soB./C.butBABBB6.Heskippedthefolkshowyesterday_______hehadatest.A.ifB.becauseC.when7.People_______spreadpaper-cuttingifthey_______schoolactivities.A.willhelp;holdB.help;holdC.willhelp;willhold8.Theoldcraftcanstayalive_______youngpeopletakeitup.A.becauseB.ifC.though9.Iadmirefolkartists_______theysticktotraditionalskills.A.ifB.soC.because

10.Ifhe_______free,he_______watchthepuppetperformance.A.is;willB.willbe;willC.is;doesBABCA题型三句型合并改写

1.Shelovesshadowpuppets.Theyshowoldstories.（用because合并）2.Youlearnpaper-cutting.YouwillknowChineseculture.（if从句前置）3.Traditionalartsareindanger.Weneedtoprotectthem.（分别用because、so写两句）4.Ifyoupracticedaily,youwillbeskilled.（改写，从句放句末）Ifyoulearnpaper-cutting,youwillknowChineseculture.①Weneedtoprotectthembecausetraditionalartsareindanger.②Traditionalartsareindanger,soweneedtoprotectthem.YouwillknowChinesecultureifyoupracticedaily.Shelovesshadowpuppetsbecausetheyshowoldstories.题型四句子改错

1.Becausemanyfolkartsdisappear,soweshouldprotectthem.2.Ifshewillpracticemore,shelearnspaper-cuttingwell.3.Ienjoypuppets