八年級(jí)下現(xiàn)在完成時(shí)全面知識(shí)點(diǎn)

1、學(xué)習(xí)必備歡迎下載一現(xiàn)在完成時(shí)概念及用法：1表示過去發(fā)生或已經(jīng)完成的動(dòng)作對(duì)現(xiàn)在造成的影響或結(jié)果。常和just（剛剛），already（已經(jīng)），yet（已經(jīng)），never（從不），ever（曾經(jīng)），before（以前），sofar（到目前為止）等時(shí)間狀語連用。2表示從過去某一時(shí)刻開始一直持續(xù)到現(xiàn)在的動(dòng)作或狀態(tài)，還有可能繼續(xù)下去，常和for或since引導(dǎo)的時(shí)間狀語連用。此時(shí)的動(dòng)詞必須是延續(xù)性動(dòng)詞。構(gòu)成：have/has（助動(dòng)詞）+V過去分詞肯定句：主語+have/has+V過去分詞+其他否定句：主語+have/has+not+V過去分詞+其他一般疑問句：have/has+主語+V過去分詞+其他肯定

2、回答：Yes,主語+have/has.否定回答：No,主語+haven't/hasn't.3常用標(biāo)志詞語already,never,ever,just,before,sofar,yet,since+過去的時(shí)間點(diǎn),for+段時(shí)間等already常用于肯定句；yet用于否定句和疑問句。二常用句型結(jié)構(gòu)辨析（）have/hasbeento/have/hasgoneto/have/hasbeenin辨析：have/hasbeento+地名”曾經(jīng)去過某地“，現(xiàn)在已經(jīng)回到原地。HehasbeentoEnglandtwice.他曾經(jīng)去過英國兩次。（現(xiàn)在已經(jīng)不在英國了）Haveyoueverbe

3、entotheGreatWall?你到過長(zhǎng)城嗎？（現(xiàn)在已經(jīng)不在長(zhǎng)城上）havegoneto+地名”已經(jīng)去某地了“，說話時(shí)該人不在現(xiàn)場(chǎng)。HehasgonetoEngland。他已去英國了。（已經(jīng)不在說話的地方，到達(dá)英國或者在去英國的路上）havebeenin+地點(diǎn)待在某地，常與時(shí)間段搭配。IhavebeeninShanghaiforthreeyears.（二）since與for區(qū)另1J：1）for其后只能接表示“一段時(shí)間”的名詞性短語，可用于多種時(shí)態(tài)。表示動(dòng)作或狀態(tài)持續(xù)的時(shí)間長(zhǎng)短；學(xué)習(xí)必備歡迎下載since其后接表示“時(shí)間點(diǎn)”的短語或從句（一般過去時(shí)）；也可以接“一段時(shí)間+ago”,常用于完成時(shí)

4、態(tài)；還用于句型“It'圓癰段+sincek般過去時(shí)態(tài)的句子表示過去某個(gè)時(shí)間發(fā)生并持續(xù)至說話時(shí)的動(dòng)作或狀態(tài)。I，velivedinthisciforfiveyears.Heusuallysleepsfor12hourseveryday.Wevestudiedheresince2009.Shehasworkedhereforfiveyears.It'stwoyearinceIcametoChina.練習(xí)：用since和for填空1. JimhasbeeninIrelandlastMonday.2. JillhasbeeninIrelandthreedays.3. Hisauntha

5、slivedinAustralia15days.4. Mikehasbeenillalongtime.Hehasbeeninhospital0ctober.2） for與since引導(dǎo)的時(shí)間狀語可以進(jìn)行相互替換Myunclehasworkedatthisfactoryforfiveyears.=Myunclehasworkedatthisfactorysincefiveyearsago.練習(xí)：IhavestudiedEnglishforfiveyears.IhavestudiedEnglish.（三）延續(xù)性動(dòng)詞與非延續(xù)性動(dòng)詞延續(xù)性動(dòng)詞表示經(jīng)過、經(jīng)歷；非延續(xù)性動(dòng)詞表示行為的結(jié)果，不能與表示一段時(shí)

6、間的狀語連用。I'veknownhimsincethen.表經(jīng)歷Hehasfinishedthework.表結(jié)果（1）延續(xù)性動(dòng)詞與非延續(xù)性動(dòng)詞的用法：非延續(xù)性動(dòng)詞與短暫性時(shí)間（點(diǎn)）連用非延續(xù)性動(dòng)詞也被稱為終止性動(dòng)詞、瞬間動(dòng)詞，表示不能延續(xù)的動(dòng)作，這種動(dòng)作發(fā)生學(xué)習(xí)必備歡迎下載后立即結(jié)束。如：open,die,close,begin,finish,come,go,move,borrow,lend,buy等。非延續(xù)性動(dòng)詞在肯定句中與表示時(shí)間點(diǎn)的狀語連用，如twoyearsago.HejoinedtheArmythreeyearsago.非延續(xù)性動(dòng)詞可用于"Itis/hasbeen+

7、時(shí)間段+sincd'句型Itis/hasbeenthreeyearssinceIboughtthebook.從我買這本書至U現(xiàn)在3年了。IbegantostudyEnglishthreeyearsago.ItissinceIstudyEnlish.ImovedtoChangchun5yearsago.Lilyfinshedherhomework2hoursago.延續(xù)性動(dòng)詞表示能夠延續(xù)的動(dòng)作，如：learn,work,stand,know,walk,keep,wait,watch,read,sleep,live,stay等。延續(xù)性動(dòng)詞可以與表示時(shí)間段的狀語for+段時(shí)間/since+時(shí)

8、間點(diǎn)/since引導(dǎo)的從句（過去時(shí)）/since+段時(shí)間+ago等連用。（2）非延續(xù)性動(dòng)詞與延續(xù)性動(dòng)詞之間的轉(zhuǎn)換：非延續(xù)性動(dòng)詞轉(zhuǎn)換為相應(yīng)的延續(xù)性動(dòng)詞，用于現(xiàn)在完成時(shí)態(tài)，時(shí)間狀語為for+段時(shí)間/since+時(shí)間點(diǎn)/since引導(dǎo)的從句（過去時(shí)）/since+段時(shí)間+agoTheoldmandied4yearsago.=Theoldmanhasbeendeadfor4years.Iborrowedthebook5daysago.=Ihavekeptthebooksince5daysago.borrow-keepbuy-havecatchacold-haveacoldputon-weargetto

9、know-knowgettosleep-sleep非延續(xù)性動(dòng)詞轉(zhuǎn)化為"be+adj、adv、prep、n”begin/start-beongoout-beoutgetto/arrivein/reach-beindie-bedeadopen-beopen學(xué)習(xí)必備歡迎下載leave-beawayfinish-beoverfallill-beillgetup-beupfallasleep-beasleepjoin-beamemberofgotoschool-beinschoolbecome-bemakefriends-befriendscome/go-be+相應(yīng)的介詞短語練習(xí)-同義句轉(zhuǎn)換：1 Iboughtthedictionarylastyear.Ihavethedictionaryoneyear.2 Thefilmbegan5minutesago.Thefilmfor5minutes.3 Hisgrandfatherdied5yearsago.Hisgrandfatherfor5years.4 Hisuncleleftthecity2hoursago.Hisunclethecity2hours.三現(xiàn)在完成時(shí)與一般過去時(shí)的區(qū)別：(1) 一般過去時(shí)表示過去發(fā)生的動(dòng)作或存在的狀態(tài)；現(xiàn)在完成時(shí)表示過去發(fā)生的某一動(dòng)作對(duì)現(xiàn)在造成的影