7、年了。现在还在教)(2)如单纯表示一段时间,或强调一段时间,虽有since一词,也不必用完成时。如:Itistwoyearssincehisfatherdied.=Hisfatherhasbeendeadfortwoyears. (3)终止性动词现在完成时的否定式,已变成一种可以延续的状态,因此可以和表示一段时间的状语连用。如:Ihaven'tleftheresince1997. arrive→behere begin(start)→beondie→bedead co
8、meback→bebackgo—be away come—be here leave→beaway(from) / (be not here) buy—have fallill(sick,asleep)→beill(sick,asleep)open →be open bo