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, buy, join, die, borrow, get up, become, open, stop等。这些动词虽然可以用于现在完成时(说明某个动作的结果还存在)，但由于它们不能延续，因此不能跟表示一段的时间状语连用。(也即现在完成时的第二个基本用法中不能使用非延续性动词)。

e.g. Jim has come back. (正)吉姆已经回来了。

Jim has come back for a month. (误) come back的动作不能延续一个月，因此错误。

(2)瞬间动词不可以用于有段时间的现在完成时态中，因此，若要解决这一问题，就应把它改为相应的延续性动词或短语，主要有以下几种：

①用相应的延续性动词

如：buy → have borrow → keep come/go/become → be put on → wear catch a cold → have a cold②转换成be+名词

如：join → be a member of go to school → be a student③转换成be+形容词或副词

如：die → be dead leave → be away begin → be on finish → be over fall asleep — be asleep open → be open get up → be up close → closed④转换成be+介词短语

如：come to/go to/arrive in (at)/get to/reach …→ be in/at… join the army → be in the army(军队)

e.g. I have borrowed the book.我已经借了那本书。

I have kept the book for two days.我已经借那本书两天了。

Jim has joined the band.吉姆已经加入那乐队了。

Jim has been a member of the band for a month.吉姆已经加入那个乐队一个月了。

His grandfather has died.他祖父已经死了。

His grandfather has been dead for 2 years.他祖父已经死了两年了。

My father has arrived in China.我父亲已经到达中国了。

My father has been in China for a week.我父亲已经在中国一个星期了。

(3)在否定句中，非延续性动词也可以与时间段连用。

e.g. I haven’t borrowed books from the library since last year.自去年以来我就没有在图书馆借过书。

Jim hasn’t come back for a year.吉姆已有一年没回来了。