文档介绍：现在完成时中延续性动词和非延续性动词
延续性动词： study learn sleep live sing dance swim
drink teach keep
非延续性动词： buy borrow lend die leave begin come / go
这些动词不能和 how long ; for ….since…连用
要把它们变成其他相应的词.
--------------------------------------------------------------------------------
（buy买了…） have/has had…
（borrow借了…） have/has kept …
（start/ begin开始了…） have /has been on
（leave离开了…） have /has been away (from)..
（来到某地/ 去某地….） have /has been in …
（die 死了…）　　　　 have/has been dead
for …
since….
。(1).I bought the book three years ago.
(2) I have had the book for 3 years.
(3) I have had the book since 3 years ago.
How long have you had the book ?
（1）He borrowed the book two months ago.
(2）He has kept the book for 2 months .
(3) He has kept the book since 2 months ago.
How long has he kept the book?
.(1) Li Mei left Jinan one year ago.
(2) Li Mei has been away from Jinan for one year.
(3) Li Mei has been away from Jinan since 1 year ago.