英语现在完成时怎样何区分(2)
(二)现在完成时用法二2——持续性用法(肯定句，疑问句中谓语动词必须是延续性动词)：表示过去已经开始，持续到现在的动作或状态。此时常与“for +一段时间?或“since+过去的点时间或从句(从句用一般过去时)以及so far(到目前为止)等时间状语连用。
for + 段时间
学习啦在线学习网 since +点时间
实例：
1)I've lived here since 1990.自从1990年以来我就住在这里。
学习啦在线学习网 = I've lived here since 13 years ago.
学习啦在线学习网 = I've lived here for 13 years.
= It is 13 years since I began to live here.
2)I haven't seen him for three years .我三年没有看见他了。
= I haven't seen him since three years ago
= I haven't seen him since 2000.
= It is 3 years since I saw him last time.
3)Mr Wang has worked in the factory since he came to the city .
自从到这个城市以来，王先生一直在这家工厂工作。
4)She's been at this school since five years ago.
学习啦在线学习网 自从五年前以来她就在这个学校。
注意：①在这类句子的肯定句和疑问句中谓语动词必须用延续性动词。短暂性动词由于动作不能持续，故不能与for(达到;累计)或since(自从。。。到现在)引出的时间状语连用。
②对for和since引导的时间状语提问要用How long
1) 他入团两年了。
学习啦在线学习网 误：He has joined the League for two years.
正：He has been a League member for two years.
2)我买这辆自行车三年了。
误：I have bought this bike for three years.
正：I have had this bike for three years.
学习啦在线学习网 2) ▲部分短暂性动词与之对应的延续性动词：
学习啦在线学习网 短暂性动词 延续性动词
学习啦在线学习网 die → be dead
borrow → keep
学习啦在线学习网 buy/catch → have
学习啦在线学习网 get up → be up
come → be in
学习啦在线学习网 finish → be over
leaver → be away
学习啦在线学习网 open → be open
学习啦在线学习网 close → be closed
学习啦在线学习网 begin → be on
become interested in → be interested in
有人可能会问：一般过去时和现在完成时所表示的动作都发生在过去，那么这两种时态有什么区别呢?
☆答：①一般过去时与具体的表示过去时间状语如：yesterday连用;强调动作在过去发生，与现在无关。
②现在完成时与自已的特征词连用，强调过去发生的动作对现在的影响或过去开始发生一直持续到现在的动作。
学习啦在线学习网 例： He saw the film last night. (过去时，表示他昨晚看过那部电影了，现在不知还要不要再看一次)
He has (ever) seen the film before.(现在\完成时，表时他已看过那部电影，现在不想再看了)
巩固练习：
学习啦在线学习网 I.按要求转换下列各句，每空一词。
学习啦在线学习网 1、He has already finished his homework.(改为否定句)
He _______ finished his homework ________.
学习啦在线学习网 2.They have found the lost books already.(改为一般疑问句，并作否定回答)
______ they _______ the lost books _______?No，they________.
3.Julia has not got home from school yet.(改为肯定句)
Julia ______ _______ ________ home from school .
学习啦在线学习网 4.You have never been to Shanghai before，_________ _________ ?(改为反意疑问句)
学习啦在线学习网 5. He’s gone to Beijing, ______ ______?(改为反意疑问句)
6.Mr Wang began to teach English in this school in 1999.(改为同义句)
学习啦在线学习网 Mr Wang _________ _________ English in this school since 1999.
7. He hasn’t left home for 3 days.(同义句)
He _____ ______ ______ home for 3 days.
8. They have lived here since 3 years ago. (对划线提问)
II.选择正确答案。
( )1.—Who is Mary ?
学习啦在线学习网 —____?I saw you talking with her at the meeting .
A.Don't you meet her yet
B.Didn't you met her yet
学习啦在线学习网 C.Haven't you met her yet
D.Hadn't you met her yet
学习啦在线学习网 ( )2.—How do you like Beijing ，Mr Black?
学习啦在线学习网 —Oh ，I ____ such a beautiful city .
学习啦在线学习网 A.don't visit
B.didn't visit
学习啦在线学习网 C.haven't visited
学习啦在线学习网 D.hadn't visited
学习啦在线学习网 ( )3.The old people ____ lonely at all since we began to visit them once a week.
A.don't feel
B.hasn't felt
学习啦在线学习网 C.haven't felt
D.didn't feel
( ) 4.We have lived here ____ five years ago.
A.when
B.since
学习啦在线学习网 C.before
D.after