延續動詞與瞬間動詞

1) 用於完成時的區別
延續動詞表示經驗、經歷; 瞬間動詞表示行為的結 果,不能與表示段的時間狀語連用。
he has completed the work.他已完成了那項工作。 (表結果)
i've known him since then. 我從那時起就認識他了。(表經歷)

2) 用於till / until從句的差異
延續動詞用於肯定句,表示"做……直到……" 瞬間動詞用於否定句,表示"到……,才……"
he didn't come back until ten o'clock.
他到10 點才回來。
he slept until ten o'clock. 
他一直睡到10點。
 
典型例題
1. you don't need to describe her. i ___ her several times. 
a. had met b. have met  c. met d. meet
  答案b. 首先本題後句強調對現在的影響,我知道她的模樣,你不用描述。再次,several times告知為反覆發生的動作,因此用現在完成時。

2.---i'm sorry to keep you waiting.
 ---oh, not at all. i ___ here only a few minutes.
a. have been  b. had been  c. was d. will be
  答案a. 等待的動作由過去開始,持續到現在,套用現在完成時。