when 和 while的用法的区别

when 和 while的用法的有什么区别，您可以详细地跟我分析下吗。因为我对这两个词很难把握。

英语中，动词按其动作发生的方式、动作发生过程的长短，可分为延续性动词和终止性动词。

　　延续性动词表示能够延续的动作，这种动作可以延续下去或产生持久影响。如：learn, work, stand, lie, know, walk, keep, have, wait, watch, sing, read, sleep, live, stay等。

　　终止性动词也称非延续性动词、瞬间动词或短暂性动词，表示不能延续的动作，这种动作发生后立即结束。如open, close, finish, begin, come, go, arrive, reach, get to, leave, move, borrow,buy等。

　　一、延续性动词

　　延续性动词表示的动作不但可以延续，而且可以产生持久的影响。常见的这类动词有：be，have，keep，know，learn，lie，live，read，sing，sleep，stand，stay，wait，walk，watch等。延续性动词的用法很广，但常见于现在完成时中的句子中，且常与for，how，long，since等引导的表示一段时间的状语或状语从句连用。例如：

　　1．I have learned more than 1，000 Chinese words since I came to China．

　　自从来到中国，我已经学会了l，000多个汉字。

　　2．We have lived in Linqing since we came here．自从来到这儿，我们就一直住在临清。

　　3．I have kept the picture for about three years．这张画我保存了大约三年。

　　延续性动词又称持续性动词，它所表示的是一种持续的动作。

　　延续性动词可与表示一段时间的时间状语连用,而非延续性动词不行

　　举个例子：

　　(1) How long have you had it? 这辆车你买了多久了？

　　[说明] 在英语中，非延续性动词不能与表示一段时间的时间状语连用。所以我们不说“How

　　long have you bought it?”因为how long 是“多久”的意思，而buy是非延续性动词，二者

　　不相配。常用的非延续性动词有：become, begin, buy, borrow, arrive, come, die, fall,

　　finish, get to know, go, join, leave, marry, start, stop等。为了表达这种意思，我们常用

　　相应的延续性动词 have,keep 或短语 “be+名词，形容词，位置副词，介词短语” 来代替非

　　延续动词。如：become---be, begin---have/ be on, borrow---keep, buy---have,

　　come--- be here/there/in…, die---be dead, finish---be over, join---be in,

　　leave---be away等。

　　例如：His father has been dead for one year.(不能用die)

　　他父亲死了一年了。

　　My brother has been in the army for two years.(不能用join)

　　我哥哥参军两年了。

　　I have kept the book for two weeks. (不能用borrow)

　　我借这本书两个星期了。

　　非延续性动词可用与现在完成时态,但由于动作是瞬时间完成的所以不能与for或since引出的时间状语连用.英语中常见的非延续性动词在完成时态中可改为相应的表示延续性的动词或短语,这时可与表示一段时间的的状语连用.

　　Now let's do some exercise!

　　Which one is correct Can you tell me

　　He has joined the Party for two years.

　　He has been a Party member for two years.

　　I have bought this computer for a month.

　　I have had this computer for a month.

　　Do this exercise!

　　I have come here . for two years

　　He has gone to Beijing. for three months

　　My mother has left that factory. for ten years

　　We have started to learn English. for 5 years

　　I have been here for two years.

　　He has been in Beijing for three months.

　　My mother has been away from that factory

　　for ten years.

　　We have learned English for 5 years.

　　The film has been on for 10 minutes

　　They have had a TV for 2 weeks.

　　They have bought a TV. for 2 days

　　The film has begun. for 10 minutes

　　I have borrowed a book. for 3 weeks

　　I have kept a book for 3 weeks.

　　He has been dead for ten years.

　　I have had a cold for several days.

while 后面只能用延续性动词，多用进行时态，也可表状态

when后面既可跟延续又可跟非延续性动词