八下Unit10现在完成时

含since或for 的现在完成时

（1）某些动词的现在完成时可表示过去某一时间开始并一直持续到现在的动作或状态

常与  for + 一段时间  或  since + 过去的时间点/动作  连用

Tom has worked in this university for twenty years. Tom在这所大学工作20年了。

He has learned about 8000 English words since he went to university. 他上大学以来学了约8000个单词了。

She has been at this school since five years ago. 她从五年前开始就一直在这个学校。

He has lived in Suzhou since 2008. 他从2008年就住在苏州。

（2）含for 和含since 的现在完成时句子可以互相转换。

She has lived here since 13 years ago.= She has lived here for 13 years. 她从13年前就住在这儿了。

I haven't seen him since three ago.= I haven't seen him for two years.我有两年没见过他了。

（3）现在完成时中的谓语动词

在现在完成时中，和一段时间连用的动词必须为延续性动词，即这个动作是可以持续的。

常见延续性动词：have，live，teach，learn，work，study，know等

常见的非延续性动词：come，go，leave，start，die，finish，become，join，buy，get married等。

非延续性动词要替换成对应的延续性动词才能与一段时间连用。

他入团两年了。He has joined the League for two years. ×

He has been a League member for two years. （√）

这辆自行车我买了三年了。I have bought this bike for three years. ×

I have had this bike for three years. （√）

（4）非延续性动词对应的延续性动词

become 非延续性——be

fall asleep非延续性——be asleep

join非延续性——be in/be a member of

borrow非延续性——keep

make friends非延续性——be friends

begin/start非延续性——be on

buy非延续性——have

finish非延续性——be over

come/go非延续性——be here/there

get up非延续性——be up

leave非延续性——be away（from）

die非延续性——be dead

open非延续性——be open

close非延续性——be closed

get married非延续性——be married

八下Unit10现在完成时