瞬间动词转换成持续性动词
瞬间动词用于完成时态不能与一段时间状语连用，须转换成持续性动词。
1.用相应的延续性动词替换的有： buy---have borrow---keep put on----wear\\be on
catch/get a cold---have a cold get to know ---know become---be
go to school ---be at school 等。 eg. 1.We have had the TV set for 3years. 2.I have kept the book for 2 weeks. 2.转换成be+名词的有：
join the army----be a soldier
join the Party---be a Party member\\be a member of go to school----be a student 等。 eg. 1.He has been a soldier for 5 years. 2She has been a student for 2 months. 3.转换成be+adj/adv. die—be dead
finish\\end—be over begin\\start---be on
leave---be away move----be out of
come\\go---be in \\be here arrive\\get to \\reach---be in go out ---be out put on---be on open---be open(adj) close---be closed
fall asleep\\ill\\sick----be asleep\\ill\\sick 等。 eg. He has been dead for 5 years. 4. 转换成be+介词短语
go to school----be at school
join the army---be in the army 等。 eg. 1.She has been in the army for 2 years. 2.He has been in school for 9 years. 5.不定式通过去掉短语中的结束性动词
get to know---know begin to study---study come to work----work
eg. 1.We have known each other for 10 years.
2.He has study Chinese for 2 years.
*瞬间动词完成时的否定式已成为一种可延性状态，因此可以和表示一段的时间状语连用。 eg. 1.I haven’t heard from her for 6 months. 2.I haven’t bought anything for 2 months.
