Unit2语法专项一般过去时的被动语态课件-外研版英语八年级下册

教学课件外研英语八年级下册

Unit2语法专项——

一般过去时的被动语态

全解精讲+分层练习学习目标1.理解主动语态与被动语态的本质区别，掌握被动语态使用场景2.熟记一般过去时被动语态的核心结构，能正确使用was/were3.掌握主动句变被动句的完整步骤，能熟练完成句型转换4.牢记动词过去分词的变化规则，能正确写出不规则分词形式5.能在填空、选择、句型转换中灵活运用该语法点解题语态的基本概念英语中语态分两种：主动语态、被动语态语态仅体现主语与谓语动作的关系，不改变句子原意主动语态：主语是动作的发出者（谁做了动作）被动语态：主语是动作的承受者（动作作用于谁）被动语态的核心使用场景动作发出者不明确，无法/无需说明例：Thestreetwascleanedearlyinthemorning.动作发出者不重要，无需突出强调例：Anewlibrarywasbuiltinourschoollastyear.说话人想刻意突出动作的承受者（表达重点）例：Thisoldphotowastakenbymygrandfatherin1990.一般过去时被动语态核心结构基础核心结构：主语+was/were+动词的过去分词补充结构：主语+was/were+过去分词+by+动作发出者时态限定：用于描述过去发生的被动动作/过去的被动状态关键：was/were的选择完全由主语的单复数决定was/were选择规则1.主语为单数名词/不可数名词→用was例：Thebookwaslostyesterday./Waterwassavedbyus.2.主语为复数名词→用were例：Thebookswerelostyesterday./Thetreeswereplanted.3.人称代词作主语：I/you→用were；he/she/it→用was例：Iwasinvitedtotheparty./Hewaspraisedbytheteacher.by短语的用法与省略原则by+动作发出者：置于句末，明确动作是“由谁做的”用法：by后接人/物的宾格（him/her/them/it）或名词例：ShewashelpedbyTom./Thedeskwasmovedbyus.省略原则：当动作发出者不明确、不重要时，直接省略by短语例：Thedoorwasopenedlastnight.（无需说明谁开的门）核心结构单数主语例句（带解析）1.Mybikewasstolenlastweek.（自行车单数，动作承受者）2.Aletterwassenttomeyesterday.（信单数，by短语省略）3.ThewindowwasbrokenbyTom.（窗户单数，by明确动作发出者）4.Thesongwassungbyafamoussinger.（歌曲单数，突出承受者）核心结构复数主语例句（带解析）1.Thetreeswereplantedlastspring.（树复数，by短语省略）2.Manybookswereboughtbymymum.（书复数，by明确动作发出者）3.Thedeskswerecleanedbystudents.（桌子复数，突出承受者）4.Somephotosweretakeninthepark.（照片复数，动作发出者不明确）主动变被动核心原则（四不变三变）四不变1.时态不变：原句一般过去时，被动句仍为一般过去时2.句意不变：仅改变表达重点，不改变句子本意3.时间/地点状语不变：位置可保留，无需改动4.固定搭配不变：动词的固定短语成分完整保留三变1.主宾互换：主动句宾语→被动句主语2.谓语变形：主动动词→was/were+过去分词3.主语后置：主动句主语→by的宾语（可省略）主动变被动四步走（步骤1：找宾语）步骤1：精准找出主动句的宾语（动作的直接承受者）找宾语技巧：先找主动句的谓语动词，再看“动作作用于谁/对着谁”示例：Heboughtanewpenintheshopyesterday.→谓语动词：bought；动作承受者：anewpen（直接宾语）→被动句主语确定：anewpen注意：若宾语是人称代词，需用宾格（him/her/them）主动变被动四步走（步骤2：变谓语）步骤2：将主动谓语变为“was/were+过去分词”1.先确定主动动词的过去分词形式（规则/不规则）2.根据新主语（原宾语）的单复数，选择was/were示例：Heboughtanewpenintheshopyesterday.→主动动词：bought（原形buy，过去分词bought）→新主语anewpen是单数→用was→被动谓语：wasbought主动变被动四步走（步骤3：加by短语）步骤3：将主动句主语变为by的宾语，构成by短语1.主动句主语是人称代词时，主格变宾格（he→him,we→us）2.by短语置于被动句句末，紧跟过去分词/状语后示例：Heboughtanewpenintheshopyesterday.→主动句主语：he（主格）→him（宾格）→by短语：byhim注意：无需明确动作发出者时，直接省略该步骤主动变被动四步走（步骤4：整句整合）步骤4：保留原句状语，整合为完整的被动句将新主语、变后的谓语、状语、by短语按顺序组合完整示例：主动：Heboughtanewpenintheshopyesterday.被动：Anewpenwasboughtintheshopyesterdaybyhim.简化：Anewpenwasboughtintheshopyesterday.（省略by短语）否定句的主动变被动（特殊规则）1.主动否定句结构：主语+didn’t+动词原形+宾语2.被动否定句结构：新主语+wasn’t/weren’t+过去分词+其他3.关键：didn’t变wasn’t/weren’t，根据新主语单复数选择示例：Betty'sdaddidn’tallowhertohavealazyday.→被动：Shewasn’tallowedtohavealazydaybyBetty'sdad.动词过去分词规则变化（三类核心）具体规则示例（动词→过去分词）一般动词直接加-edclean→cleaned；walk→walked以e结尾的动词直接加-dlike→liked；close→closed辅音字母+y结尾，变y为i加-edcarry→carried；study→studied重读闭音节结尾：辅+元+辅，双写末尾辅音加-edstop→stopped；plan→planned过去分词与过去式规则变化形式一致，可结合记忆动词过去分词不规则变化（高频必背）动词原形过去式过去分词taketooktakendodiddoneseesawseenwritewrotewrittenbreakbrokebrokenbuildbuiltbuiltholdheldheldhidehidhidden不规则变化拓展必背

动词原形过去式过去分词speakspokespokengivegavegivenmakemademadesavesavedsavedpullpulledpulleddiscussdiscusseddiscussedwaterwateredwateredcarrycarriedcarried小练习1——写出动词的过去分词

请写出下列动词的过去分词形式1.clean→__________2.like→__________3.carry→__________4.take→__________5.do→__________6.break→__________7.build→__________8.write→__________cleanedlikedcarriedtakendonebrokenbuiltwritten主动变被动典型例题讲解（1）例题：Theteacherpraisedhimforhisprogress.（主动）解析步骤：1.找宾语：him（动作承受者）→被动主语：He2.变谓语：praised→praised（过去分词），He单数→waspraised3.加by短语：theteacher（主动主语）→bytheteacher4.整合：Hewaspraisedforhisprogressbytheteacher.主动变被动典型例题讲解（2）例题：Theybuiltanewplaygroundlastyear.（主动）解析步骤：1.找宾语：anewplayground→被动主语2.变谓语：built→built，单数→wasbuilt3.加by短语：they→bythem4.整合：Anewplaygroundwasbuiltlastyearbythem.主动变被动典型例题讲解（3）例题：Shewrotealettertoherfriend.（主动）解析步骤：1.找宾语：aletter→被动主语2.变谓语：wrote→written（不规则），单数→waswritten3.加by短语：she→byher4.整合：Aletterwaswrittentoherfriendbyher.语法易错点提醒（1）1.混淆过去式与过去分词：被动语态必须用过去分词，不可用过去式错误：Thewindowwasbroke.正确：Thewindowwasbroken.2.单复数搭配错误：主语复数却用was，单数用were错误：Theflowerswaswatered.正确：Theflowerswerewatered.语法易错点提醒（2）3.多余添加助动词：被动语态已有was/were，无需加did/do错误：Shedidwastakenhome.正确：Shewastakenhome.4.by短语后用主格：by是介词，后接宾格，不可用主格错误：byhe正确：byhim5.省略必要的过去分词：was/were后必须跟过去分词，不可空缺专项习题1——句型转换（主动变被动）1.WefinishedtheworklastFriday.2.Hebrokethecupwithaknife.3.Mymothermadeacakeformybirthday.4.TheyinvitedTomtothepartylastnight.5.Theteacheraskedustodoourhomeworkcarefully.TheworkwasfinishedbyuslastFriday.Thecupwasbrokenbyhimwithaknife.Acakewasmadeformybirthdaybymymother.Tomwasinvitedtothepartybythemlastnight.Wewereaskedtodoourhomeworkcarefullybytheteacher.专项习题2——用所给动词的正确形式填空1.Theoldbuilding______________(pull)downlastyear.2.Thesephotos_____________(take)inBeijingin2023.3.Theproblem______________(solve)bythestudentsyesterday.4.Anewroad_____________(build)nearourhomelastmonth.5.Hishomework_____________(check)bytheteacherthismorning.waspulledweretakenwassolvedwasbuiltwaschecked专项习题3——单项选择1.Thelittleboy______byhismotherjustnow.A.washuggedB.huggedC.ishuggedD.hugs2.Manytrees______inourcitylastspring.A.wasplantedB.wereplantedC.plantedD.plant3.Thebook______byLuXunin1921.A.wroteB.iswrittenC.waswrittenD.writes4.—When______thebridge______?—Lastyear.A.was;buildB.was;builtC.is;builtD.did;build5.Mybike______yesterday,soIhadtowalktoschool.A.waslostB.lostC.islostD.losesABCBA专项习题4——改错