短暂性动词，延续性动词和现在完成时延续性动词是指动作发生后还可以延续一段时间或者相当长的一段时间。如：live,work, study, learn, sleep等，延续性动词可以和表示一段的时间状语连用。短暂，性动词是指动作一旦发生就立即结束。它不能和一段时间连用。这类动词有：go,come, arrive, leave, begin, start, join, marry 等；在否定句中，短暂性动词可以和表示一段时间的状语连用。We havent heard from Jane for a long time.短暂性动词的肯定式不能与表示一段时间的for或since或how long等状语连用。值得 注意的是，表示一段时间的状语除了 “for+段时间”外，还有since+n./从句(时间点)， since+时间段+ago，疑问词 how long， in the past+时间段，all these+时间段，from七。(时间点)以及till/until +n./句子等等。例如：.I have received his letter for three days( X) I have received his letter. (V)How long did she leave . (X) How long has she been away (V)如果短暂性动词与表示一段时间的时间状语连用，必须将短暂性动词改为延续性动词。 现归纳总结一下由非延续性动词到延续性动词的转换:arrivebe here!?begin(s tart) be ondie be deadcome backbe back leave be away (from) fall ill(asleep)beill( asleep)finish be overput on wear 或 be onopen be openclose be closedjoin be in/ be a member ofgo to schoolbe a studentborrowkeepcat ch(a cold) have(acold)get to know know begin to stu dys tudy come to workwork move to live in finish/end be over come to be inget upbe uparrivebe herebuy/ge thavesit down be seated除了用上面的转化形式之外，还可以用其他的表达形式：A. It is或者It has been+时间+since (动词用过去式),B.主语+谓语(过去时)+时间+ago。例如：Its five days since I received his letter.His father died three years ago.看一个句子可以用以下几种说法：他离开上海已经3天了。He left Shanghai three days ago.He has been away from Shanghai for three days/since three days agoIt is/has been three days since he left Shanghai.Three days has passed since he left Shanghai.几点注意事项：(1)have been(to)与 have gone( to)的区别：have been（ to）表示“去过某地（现在已经回来了）”，可用于各人称；have gone（to）表示“去某地了（说话时某人不在当地）”，可能在去的路上，可能已在某地， 也可能在回来的路上，总之，人不在这里。常用第三人称作主语。前者可与once,never, several times等连用，后者则不能。如：They have been to Beijing twice.他们去过北京两次。He has gone to Beijing 他去北京了。注意比较 has gone to, has been to, has been in 的意义：He has gone to Amercia.（他到美国去了。 他不在这里）He has been to Amercia.（他去过美国。 现已回来）He has been in Shanghai.（他在上海呆过。现在不在上海）He has been in shanghai for years.（他在上海多年。现在还在上海）（2）终止性动词现在完成时的否定式，已变成一种可以延续的状态，因此可以和表示一段时 间的状语连用。如：I haven t left here since 1997.自从1997年以来，我一直没有离开过这儿。另外，动词的延续性与非延续性还体现在这两种句型中：延续性动词的肯定式+til l/un til 短暂性动词的否定式+till/ until 请看例句：We waited until he came.I didnt go to bed until my father came back home last night.短暂性动词，延续性动词和现在完成时练习I. 句型转换：1. Mr. Li began to teach English in this school in 1999.（同义句）Mr. LiEnglish in t his school since 1999.2. The factory opened ten years ago.（同义句The fac toryfor ten years.3. John lef t Beijing t hree years ago. （同义句）Three yearsJohnBeijing.John Beijing three years.4. His company opened in 2003.（同义句His companysince 2003.5. My fat her bough t the car half a year ago. （同义句%My fat herthe carhalf a year.6. We got to know each other for about 15 years.（同义句Weeach ot herabo ut 15 years.7. The film began ten min utes ago. （同义句The filmfor ten min ut es.8. I borrowed t his book two weeks ago. （同义句It his book for two weeks.9. My father came back the day before yesterday.My fat her hasfor two days.uncle bought the new car two months ago.My uncle hasthe new cartwo months ago.11. 用 have been 和 have gone 填空。1. Mother isnt here. She to the barbers.2. you ever abroad before4. Tom and Mary have just come in. They to a party.5. Tom and Mary arent here. They to a Party.6. My father to New York. He left this morning.12. The students to the cinema to see a film today. Now they are back.14. Mr. and Mrs. Smith to London now. They t h e r e twice already.18. Miss Linever to China before.19. Where you The meeting has already begun.20. Where he I cant find him anywhere.III. 选择题1. The bookshop for eight years.A has been open B has been opened C has opened D has open2. I the club for 5 years so far.A. joinedB. have joined C. have been in3. The factory since the February of 1988.A . has been open B. has opened C. was open D. opened. Mary and Rose friendssincethey met in 2000.A.have madeB.havebeenC. madeD. have becomemustnt _ untilhecomesback.A.be awayB.leaveC.be left for a week now.meetingA. has finishedB. has ended C. has been overGao this school for nearly 5 years.A. has been in B. has come to C. has taught a teacher for 4 years .A. has been B. has become C. was D. became9. I home for a week.A. have returned B. have been back C. returned10. How long he A. died B. has, died C. has, been dead11. He at eight yesterday afternoon.A. slept B. was sleeping C. has sleep D. had slept the car for a week.A. bought B. has bought C. has hadlong you ill Two weeks.A. did fall B. have, fell C. have, been2000, he his hometown.A. has left B. has moved away C. has been away fromlend you the book , but you can only it for 2 days.A. borrow B. keep C