动词按其动作发生的方式、发生过程的长短可分为延续性动词与非延续性动词。
一.延续性动词表示能够延续的动作,如:learn, work, stand, lie, know, walk, keep, have, wait, watch, sing, read, sleep, live, stay等。延续性动词可以与表示时间段的状语连用。
表示时间段的短语有:for+一段时间,for 2 years; since从句,since he came here; since+时间点名词,since last year, since 5 days ago; how long; for a long time等。
例:He has lived here for 6 years. You can keep the book for 5 days. I stayed there for 2 weeks last year. How long did you stay there last year?
二.非延续性动词也称终止性动词、瞬间动词,表示不能延续的动作,这种动作发生后立即结束。 如:open, die, close, begin, finish, come, go, move, borrow, lend, buy等。
非延续性动词在肯定句中与表示时间点的状语连用,如:two years ago; at 5 o'clock;
例:He died 5 years ago.
否定的终止性动词可以与表示时间段的时间状语连用。例:I haven't left here for 3 years. I haven't heard from him for 3 weeks.
三.延续性动词与非延续性动词之间的转换:leave --- be away, borrow --- keep, buy --- have, begin/start --- be on, die --- be dead, finish --- be over, join --- be in+组织机构, be a member of+组织机构, open sth --- keep sth open, fall ill --- be ill, get up---be up, cat