人教版八年級下英語unit8.9.10單元現在完成時講解和練習現在完成時（I）第八單元語法知識定義：（1）表示過去發生或已經發生的動作對現在造成的影響或結果,這個影響和結果對現在還必須存在.常與already（已經）,yet（已經，還）,just（剛^U）,ever（曾經）,never等詞連用already:常用于肯定句或疑問句（均表示：已經）.yet:常用于否定句（表示：還、尚）,疑問句末尾（表示：已經）.現在完成時的構成及句型結構：（注：過去分詞的變化分規則變化與不規則變化，規則變化與動詞原形變過去式一樣，不規則變化見教材1?肯定句：主語+have/has+過去分詞+其他+時間.2?否定句：主語+haven'thasn't+過去分詞+其他+時間.3?—般疑問句：Have/Has+主語+過去分詞+其他+時間？肯定回答：Yes,主語+have/has.否定回答：No,主語+haven't/hasn't.4?特殊疑問句：特殊疑問詞+have/has+主語+過去分詞+其他+時間？定義：（2）表示從過去開始一直持續到現在還有可能繼續持續下去的動作或狀態。(3)現在完成時與一般過去時的區別：現在完成時屬于現在時態的范圍，不能和表示過去的時間狀語連用，如yesterday,lastnight,threeweeksago,in2019等.一般過去時只表示過去的動作或狀態，和現在不發生關系。一般過去時可以和表示過去的時間狀語連用.例題：1.you(clean)theroom?Yes,we(do)thatalready.Whenyou(do)it?We(do)itanhourago.he(see)thisfilmyet?Yes,Whenhe(see)it?Heitlastweek.I(read)thenoveltwice.It'sinteresting.Mr.Chen(give)upsmokinglastyear.7.She(go)toPairs,hasn'tshe?---Yes,Howshe(go)there?She(go)therebyair.現在完成時(II)第九單元語法知識構成：含有be動詞的現在完成時的謂語部分由“have/has+been+to+地點”構成，表示：曾經去過某地…(been是be的過去分詞，不規則變化)基本句型：⑴肯定句：主語+have/has+been+to+地點.(2)否定句：主語+haven't/hasn't+been+to+地點.⑶一般疑問句：Have/Has+主語+been+to+地點？肯定回答：Yes,主語+have/has.否定回答：主語+haven't/hasn't.(4)特殊疑問句：特殊疑問詞+have/has+主語+been?

eg:Wherehaveyoubeen?3.用法：用來表示之前已經發生和完成度的動作與狀態，其結果卻和現在有聯系.動作和結果發生在過去，但它的影響現在還在.可以和never,ever,once,twice,three/four???times等副詞連用.eg:TheyhavebeentoChongqingtwice.IhaveneverbeentoSichuan.HassheeverbeentoHainan?3.區別：(1).have/hasbeento+地點表示：曾經去過某地，已經回來了(2).have/hasgoneto+地點表示：去了某地，還沒有回來eg:ShehasbeentoShanghai.(她去過上海，已經回來了)ShehasgonetoShanghai.(她去了上海，還沒有回來)(3).havebeenin表示“在某地呆了多少時間”，常與時間段狀語連用eg:IhavebeeninShanghaiforthreeyears.我到上海已有三年了。HehasbeeninLondonforhalfamonth.他來倫敦已有半個月了。(4).havebeenon表示“已經開始了多久表示持續性”eg:Thefilmhasbeenonfortenminutes.電影已經開始了10分鐘了。例題：—Whereisyourbrother?—Hetheshop.He'llbebacksoon.—youevertoAmerica?—Yes,INewYorktwice.—DavidAustralia.—I'msurehehasalreadyarrived.—IsBennyhere?—No,hetheschoollibrary.Heleftfiveminutesago.Mikeandhisparentsthesouthforhalfayear.Mumisnotathomenow.shetheshop.Youcan'tfindhim.HeXi'an.Mr.Zhangthisschoolfortenyears.Heknowseveryonehere.Miss.BrownChinathreetimes.ItheWestlake,Look,Ihavetakenmanyphotosofit.TomJim'shome,buthehasn'tcomeback.Wethebookshopandboughtmanybooks.MyparentsShandongfortenyears.Ialready(see)thefilm.I(see)itlastweek.he(finish)hisworktoday?Notyet.Myfatherjust(come)backfromwork.Heistirednow.Where'sLiMing?He(go)totheteacher'soffice.I(work)heresinceI(move)herein

2019.SofarI(make)quiteafewfriendshere.HowlongtheWangs(stay)here?Fortwoweeks.21.I__just___(finish)myhomework.re22.He(go)toschoolonfooteveryday.23.you(find)yoursciencebookyet?24.Mylittlebrother(collect)shellsfortwoyears.25.______Ben___(read)thebook?Yes,hehas.He___itlastyear.26.Julia(visit)thenaturemuseumtwice.27.-27.-Anna,you(see)China'sGotTalent（中國達人秀）？-Ofcourse.Iitlastweekend.I(buy)anewMP4already.Iityesterday.Howyou(come)toschoolthismorning?he(hear)ofthestorybefore?-Yes,he.Heitlastmonth.現在完成時（III）第十單元語法知識動詞按其動作發生的方式，發生過程的長短可分為延續性動詞與非延續性動詞。1.延續性動詞：表示能夠延續的動作，也可以表示經驗與經歷.eg:learn,work,stand,lie,walk,sleep,keep,wait,watch,sing,read,stay,live..?延續性動詞可以與for和since引導的時間狀語連用：eg:Hehaslivedherefor6years.（他在這兒住了六年了，一直住在這兒，live是延續性動詞，并且很有可能繼續居住下去）Ihaveknownhersincethen（.自從那時起我就認識她了，一直都認識，know是延續性動詞）非延續性動詞：也成終止性動詞或瞬間動詞，表示不能延續的動作，這種動作發生后立即結束.eg:open,close,begin,finish,come,go,move,borrow,lend,buy,die…非延續性動詞不能與for和since引導的時間狀語連用，常用的時間狀語有twoyearsago,at5o'clock,yesterday,thedaybeforeyesterday,thismorning等表示過去的時間.eg:Hisgrandmotherdied10yearsago.Shefinishedtheworkat6o'clock.2.非延續性動詞與延續性動詞之間的轉換（常用）（1）.轉化為相應的延續性動詞，用于現在完成時態eg:borrowfkeepbuyfhaveputonfweargettoknowfknowgettosleepfsleepcatchacoldfhaveacold(2)?轉化為“be+形容詞/副詞/介詞/名詞”begin/startfbeongooutfbeoutdiefbedeadpenfbeopengetto/arrivein(at)/reachfbein+地點leavefbeaway(from)finishfbeoverfallillfbeillgetupfbeupfallasleepfbeasleepjoinfbein+活動/組織gotoschoolfbeinschoolbecomefbemakefriendsfbefriendsclosefbeclosedgotobedfbeinbedcome/gofbe+相應的介詞短語例：下面是句子的同義句轉換將原句一般過去時改成現在完成時eg:1.Theoldmandiedfouryearsago.（一般過去時）Theoldmanhasbeendeadforfouryears.（現在完成時，將die變為bedead）Theoldmanhasbeendeadsincefouryearsago.（現在完成時，since跟過去的時間點）Iborrowedthebookfivedaysago.Ihavekeptthebookforfivedays.Ihavekeptthebooksincefivedaysago.Heboughtthebikethreeyearsago.Hehashadthebikeforthreeyears.Hehashadthebikesincethreeyearsago.Shewenttoschooltwodaysago.---Shehasbeeninschoolfortwodays.Shehasbeeninschoolsincetwodaysago.Mysisterbecameanurseoneyearago.Mysisterhasbeenanurseforoneyear.Mysisterhasbeenanursesinceoneyear.例題：1.LiLeijoinedthePartythreeyearsago.（同義句）LiLeithePartythreeyears.LiLeithePartythreeyearsago.MyfatherleftGuizhoulastweek.（同義句）MyfatherGuizhouaweek.MyfatherGuizhoulastweek.Thefactoryopenedin2018.（同義句）Thefactorytenyears.Thefactorysince2018.M