现在完成时

延续性与非延续性动词在现在完成时态中的使用：1.有一些动词是瞬间动词，也叫非延续性动词，这些动词一发生就结束了，常见的有：come、go、arrive、reach、leave、begin、start、leave、buy、join、die、borrow、become、getup、open、stop等，这些动词虽然可以用于现在完成时，但由于他们不能延续，所以不能跟表示一段的时间状语连用，若要解决这个问题，就需要把其改为相应的延续性动词或短语，主要有以下几种：A.变为相应的延续性动词，如：buy—haveborrow—keepcome/go/become—bePuton—wearcatchacold—haveacoldB转化成be+名词，如：join—beamemberofgotoschool—beastudentC转化成be+形容词或副词，如：die-bedeadleave—beawaybegin—beonfinish-beoverfallasleep-beasleepopen-beopengetup-beupclose-closedD.转化成be+介词短语，如;cometo/goto/arrivein(at)/getto/reach—bein(at)jointhearmy--beinthearmyEg:Ihaveborrowedthebook.Ihavekeptthebookfortwodays.Jimhasjoinedtheband.Jimhasbeenamemberofthebandforonemonth.Hisgrandfatherhasdied.Hisgrandfatherhasbeendeadfortwoyears.MyfatherhasarrivedinShanghai.MyfatherhasbeeninShanghaiforoneweek.2.在否定句中，非延续性动词也可以与时间段连用Eg:Ihaven’tborrowedbooksfromthelibrarysincelastyear.Jimhasn’tcomebackforoneyear.