1. 非延续性动词可用来表示某一动作完成,因此可用于现在完成时。如:
The train has arrived. 火车到了。
Have you joined the computer group? 你加入电脑小组了吗?
2. 非延续性动词表示的动作极其短暂,不能持续。因此,不可与表示一段时间的状语连用(只限肯定句)。如:
(1) 他死了三年了。
误:He has died for three years.
正:He has been dead for three years.
正:He died three years ago.
正:It is three years since he died.
正:Three years has passed since he died.
(2) 他来这儿五天了。
误:He has come here for five days.
正:He has been here for five days.
正:He came here five days ago.
正:It is five days since he came here.
正:Five days has passed since he came here.
(1)、(2)句中的die、come为非延续性动词,不能与表示“时间段”的状语连用。那么,应如何正确表达呢?可以采用下面的四种方法:
a. 将句中非延续性动词转换为相应的延续性动词,如上面两例中的第一种正确表达方式。下面列举几例: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.→keep sth. open, fall ill→be ill, get up→be up, catch a cold→have a cold。
b. 将句中表示“时间段”的状语改为表示过去确定时间的状语,如下面两例中的第二种正确表达方式。
c. 用句型"It is+段时间+since..."表达原意,如上面两例中的第三种正确表达方式。
d. 用句型"时间+has passed+since..."表达原意,如上面两例中的第四种正确表达方式。
3. 非延续性动词可用于现在完成时否定式中,成为可以延续的状态,因而可与表示“时间段”的状语连用。如:
He hasn’t left here since 1986. 从1986年以来他就没离开过这里。
I haven’t heard from my father for two weeks. 我已经两周没收到我父亲的来信了。