语法精讲---现在完成时

语法精讲八：动词时态（四）现在完成时
一、定义
表示过去发生或已经完成的动作对现在造成的影响或结果，或从过去已经开始，持续到现在的动作或状态。

二、结构
主语+ have / has + 动词过去分词
(注：过去分词规则变化方式同过去式，不规则变化见不规则动词表)
Eg. I have finished my homework.
He has found his pen.
三、句式
1、陈述句：
主语+have/has done....
2、一般问句及简略回答：
Have/has +主语+done....?
Yes, 主语+have/has; No, 主语+haven’t/hasn’t.
3、否定句：
主语+haven't/hasn’t + done...
四、用法及标志词
1.表示过去发生或已经完成的动作对现在造成的影响或结果
1) 标志词:
already：多用于陈述句，位于have/has后，有时位于句尾。

Eg. I have already finished my homework.
yet ：用于疑问句和否定句，位于句尾。

Eg. Have you found your lost book yet ?
I haven't had breakfast yet.
ever ：多用于疑问句，问初次经历。

Eg. Has your father ever spoken to a foreigner?
never ：用于否定句，位于have/has后
Eg. We've never met such a tall man.
before ：可用于各句式，位于句尾。

Eg. I have read this book before.
He hasn't been abroad before.
Have you flown to Hainan before?
2) 无标志词
（注：根据具体语境判断时态）
2.表示从过去已经开始，持续到现在（还可能继续去）的动作或状态。

标志词:
1) for +一段时间
Eg. We have lived in this city for ten years.
2) since +过去点时间
since +一段时间+ago
since +从句（从句用一般过去式）
Eg. He has worked here since 1990.
She has taught in this school since two years ago.
We have known each other since we met.
3) so far, once/twice/ three times, all one's life
Eg. They have learnt 2000 words so far.
Tom has seen the film twice.
Her father has worked in the factory all his life.
4) in the past +一段时间
during the last +一段时间
Eg. They have built many high buildings in the past three years.
Great changes have taken place in Handan during the last two years.
3. have / has been to(去而已归)与have / has gone to（去而未归）区别
Eg. He has been to Handan.（去过邯郸，人已回来）
He has gone to Handan.（去邯郸了，人在路上或在邯郸）
五、使用现在完成时应注意的问题
1.现在完成时与一般过去时的区别
1）一般过去时表示过去的事实，强调动作发生的时间、地点、方式；
2）现在完成时表示过去动作与现在的关系，强调对现在的影响或产生的结果Eg. A) I had my lunch at twelve at school. 我十二点在学校吃的午饭。

(强调吃饭的时间、地点，不涉及现在情况)
B) I have had my lunch. 我吃过午饭了。

(强调吃饭对现在的影响是饱了，不须再吃了)
2.非延续性动词（短暂性动词）的用法
常用的非延续性动词，如come, go, leave, arrive, join, die, begin,finish, open, close, buy, borrow, get up等，它们的完成时不能与段时间状语连用，若句中有表示一段时间的状语，需将非延续性动词改为延续性动词形式。

Eg. （误）He has come to Handan for two weeks.
（正）He has been in Handan for two weeks.
e to sp/go to sp.= be in sp.
b.leave = be away (from)
Eg. They left the town two days ago.
They have been away from the town since two days ago.
c.join = be in = be a member of
Eg. She joined this club three months ago.
She has been in this club for three months.
She has been a member of this club for three months.
d.die = be dead
Eg. The man died five years ago.
The man has been dead for five years.
e.begin = be on
Eg. The film began ten minutes ago.
The film has been on for ten minutes.
f.buy = have
Eg. We bought the house two years ago.
We have had the house for two years.
g.borrow = keep
Eg. She borrowed the books a week ago.
She has kept the books for a week.
h.open = be open close = be closed
get up = be up finish = be over
3、固定句式：
It is / has been + 段时间+ since 从句(用一般过去时）
Eg. It is /has been two days since he left for America.
六、练习题
（）1.When he arrives at the bus stop, the bus _____ for 20 minutes.
A. has left
B. had left
C. has been away
D. had been away （）2. I ______ the League for 5 years so far.
A. joined
B. have joined
C. have been in
D. joined in
（）3.The factory ____ since the February of 1988.
A . has been open B. has opened C. was open D. opened （）4.His parents look sad. Maybe they ______what's happened to him.
A. knew
B. have known
C. must know
D. will know （）5. How long _______ he ________ ?
A. have died
B. has, died
C. has, been dead
D. had died （）6.He has _______ been to Shanghai, has he ?
A. already
B. never
C. ever
D. still
（）7.He ________ the car for a week.
A. bought
B. has bought
C. has had
D. buy （）8.—Our country ______ a lot so far .
—Yes. I hope it will be even ______.
A. has changed; well
B. changed; good
C. has changed; better
D. changed; better
（）9.It _____ ten years since he came Chengdu.
A. is
B. has
C. will
D. was Keys:CCABC BCCA。