在现在完成时里面，for+一段时间和since+时间点都是表示一种延续性的时间，这个时候终止性动词要改为延续性动词。e.g. He has had this new bike for a week.
我们不能说he has bought this new bike for a week.His grandfather has been dead for two years.The film has been on for 10 minutes.类似的还有不少，可以去搜下短暂性动词如何转换为延续性动词...
非延续动词（也就是终止性动词） 转化为延续动词一般都是加be的leave→be away, borrow→keep, buy→have, begin/start→be on, die→be dead, move to→live in, finish→be over, join→be in/be a member of, open sth.→ke...
