定义： 表示过去发生或已经完成的某一动作对现在造成的影响或结果，或从过去开始一直延续到现在的动作或保存的状态。
结构： 主语+ have / has （not）+ 动词的过去分词（P.P）
助动词have与I， you ，they和复数名词连用.
助动词has与第三人称单数she，he，it，单数名词连用.
注意：现在完成时常见缩略词：
I have=I’ve you have=you’ve
they have=they’ve we have=we’ve
have not=haven’t has not=hasn’t
She has= she’s he has=he’s
it has=it’s
一般疑问句形式与答语：
Have you/they /I/复数+P.P？/
Yes, I/they/you have. No, I/they/you haven’t.
Has she/he/it+P.P？?
Yes, she/he/it has. No, she/he/it hasn’t.
I.动词变化：
A.规则变化（与过去式相同）：
1) 一般在动词词尾直接加ed。如：
pick → picked → picked; wish → wished → wished; stay → stayed → stayed
2) 以不发音的e结尾的动词后面加d。如：like → liked → liked; hope → hoped → hoped; phone → phoned → phoned
3)以“辅音字母 + y”结尾的动词，变y为i，再加-ed。如：
study → studied → studied; hurry → hurried → hurried; reply → replied → replied
4.)词尾只有一个辅音字母的重读闭音节动词，要双写辅音字母，再加-ed。如：stop → stopped → stopped; clap → clapped → clapped
B.不规则变化：
参见课本P136--137 verb动词 Irregular verb 不规则动词Past tense过去式
past participle过去分词
II.用法：1.过去发生的动作对现在造成的影响或结果。和never,ever,just,before,等状语连用。
I have just had my breakfast.
They have already handed in their homework.
I have never been to Taiwan./Has she ever been to Japan?
They have arrived in Guangzhou before I set out.我出发前他们已经到达广州了。
already “已经” ; yet “仍然, 还”这两个副词常常用于完成时态, 其中already
常用于肯定句, yet常用于否定句和疑问句中。
如: Has Jim finished his work yet?Jim has already finished his work.
Mother hasn’t come home yet. 妈妈还没回来。
Haven’t you read The Call of the Wild yet?
2.现在完成时动词可以表示开始于过去持续到现在(也许还会继续进行下去)的动作或状态，常与for+一段时间或since+时间点或引起的一段时间状语连用（含有一般过去时从句）。
Mr Xu has taught in No.4 High School for sixteen years/since 2001/he finished the college in 2001 .How long has he taught in this school?When has he taught in this school?
The Smiths have lived here for three years/since 2014.
I have studied English since four years ago. 我从去年开始学习英语。
She has lived in Beijing for five years. 她住在北京已经五年了。
We have learned 1,500 English words since we came to this school.
自从我们来到这个学校，我们已经学习了1500个英文单词.
注意: come, go , leave, arrive, buy, lose, receive, join, die, bury 和marry 等动词所表示的动作是一时的, 不能延续的, 故不能与for …, since …等开头的表示一段时间的状语连用。不过, 这些词用于否定句则可以与表示持续的时间状语连用，即动作的不发生是可以持续的。
不能说: *He has come to Beijing for two years.
*He has bought that book for three weeks.
*He has joined the Army for one and a half years.
*His grandma has died for nine months.
* I have received his letter for a month.
可以说:
He has been in Beijing for two years.
He has had that book for three weeks.
He has been in the army for one and a half years.
His grandma has been dead for nine months.
I haven't received his letter for almost a month.
也可以这样说
It is two years since he came to Beijing.
It is three weeks since he bought that book.
It is one and a half years since he joined the Army.
It is nine months since his grandma died.
It is a month since I received his letter.
3. 现在完成时与一般过去时的区别：A.现在完成时表示过去发生或已经完成的某一动作对现在造成的影响或结果，或从过去开始一直延续到现在的动作或保存的状态，强调的是现在的情况，不能和表示过去的时间状语连用（如：in 1990，last Sunday 等）。
B.一般过去时只表示过去的动作或状态，和现在不发生关系（即动作或状态在现在已经结束），它可以和表示过去的时间状语连用。
C.现在完成时把过去的动作和现在的结果联系起来， 一般过去时只限于表示过去的动作本身, 与现在的结果无关。现在完成时与一般过去时在意义上的区别举例如下：
I have cleaned my room. (My room is clean now.)
我已经打扫过我的房间了。
I cleaned my room last week. (I did it in the past.)
我上周打扫了我的房间。
Father has gone to Amoy. (He went to Amoy and he is not here now.)
爸爸已经去厦门了。
注：Have (has) gone to 意为“到某地去了”，表示到了某地或正在去某地的途中。总之，说话时该人不在现场，一般不用第一、二人称代词作主语。
如: —Where is Tom? 汤姆在哪里？ —He has gone to the bookshop. 他到书店去了。
They have bought a dictionary. (They bought a dictionary and they have it now.)
他们买了一本字典。
注意: 现在完成时不能和明确指出时间的状语(如: yesterday, last, year, in 1976, two days ago, just now, when she came in 等)连用，但可以和不明确指出时间的状语(如: already, yet, ever, never, sometimes, always, often, before, once, twice, recently, lately等)连用；也可以和表示包括现在在内的时间状语(如：today, this morning, this week, this year等)连用。
*4.现在完成进行时和现在完成时的区别:都可以表示“从过去开始一直持续到现在”这一概念, 有时两者可以互相代用, 但前者多用于口语。区别在于：
1).相同点：
当表示过去发生且一直持续到现在的动作时，两者通用；现在完成进行时只是现在完成时的一种强调时态而已。如：
I have played for half an hour since I began to play tennis.
= I have been playing for half an hour since I began to play tennis.
2).不同点：
(1)当表示过去发生的动作，已经完成，强调对现在产生的结果或影响时，只能用现在完成时。如 I have copied these problems.
(2)当使用现在完成进行时的时候，主句的谓语动词.要用延续性动词；而当使用现在完成时的时候，是否使用延续性动词，视具体情况而定。
(3)不能用于进行时的动词(如like, want等) ，也不能用于现在完成进行时。而现在完成时无此。如 I have been liking her for a long time. ×
I have liked her for a long time. √
III.相关练习：
A.该写句子
1.My father came back from the bookshop just now.
My father ______ just ________ ______ the book shop.
2.He began to learn Chinese in 2001.
He _____ _______ Chinese since 2001.
3.He has had the motorbike for two years.
It’s two years ______he ________ the motorbike.
He ________ the motorbike two years ______.
Two years ______ ______ since he ______ the motor bike.
4Jenny has already been to Beijing.(改为否定句)
Jenny to Beijing .
5.That dog died last month.
That dog_______ ________ ________since last month.
6 I borrowed the library book two days ago.
I _______ _______the library book________ two days
B.翻译
1. 她成为一名护士已经三年了。
She a nurse three years.
2. 我五年前就认识李雷了。
I Lilei five years ago.
3. 那些相片我已经还给他了。
I the photos to him.
4. 我们来到这个学校后，他就一直教我们数学。
He us math since we the school.
5. 我刚丢了我的历史书。
I my history book.
C.选择填空：
1. I ________heard of that story before.
A. don’t have B. not have C. have not D. not to have
2. She’ s never been to that factory,_________?
A. is she B. was she C. does she D. has she
3. Have you made dumplings__________? No, I haven’t.
A. just now B. yesterday C. ago D. before
4. Tom________ ill since last night.
A. was B. is C. has been D. be
5. How long have you________ Nanjing?
A. gone to B. been to C .been in D. went to
6. How many times has Jim _______that park? Twice.
A. gone to B. been to C. been in D. went to
7. I’ve______ this dictionary for half a year.
A. bought B. had C. lended D. borrowed
8. She won’t go to the cinema this evening because she________the film before.
A. has seen B. saw C. sees D. is seeing
9. —Why is Mr. Yang still in the teachers’ office?
—Maybe he ________ his work yet.
A. doesn’t finish B. hasn’t finished
C. haven’t finished D. haven finished
10. —Do you know the movie Lost in Thailand?
—Yes. I ______ it twice. It’s funny.
A. saw B. see C. have seen D. will see
11. — I’m sure Andrew will win the first prize in the final.
— I think so. He ________ for it for months. (2008江苏)
A. is preparing B. was preparing
C. had been preparing D. has been preparing
12. By the time he realizes he _________ into a trap, it’ll be too late for him to do anything about it. (2008山东)
A. walks B. walked C. has walked D. had walked
13. So far this year we _______ a fall in house prices by between 5 and 10 percent. A. saw B. see C. had seen D. have seen
14. Cathy is taking notes of the grammatical rules in class at Sunshine School, where she ______ English for a year. (2007湖南)
A. studies B. studied C. is studying D. has been studying
15. Danny _________ hard for long to realize his dream and now he is popular.
A. works B. is working C. has worked D. had worked
16. —I have got a headache.
—No wonder. You_________ in front of that computer too long. (2007江西)
A. work B. are working C. have been working D. worked
17. The unemployment rate in this district______ from 6% to 5% in the past two years. A. has fallen B. had fallen C. is falling D. was falling
18. Now that she is out of job, Lucy ___ going back to school，but she hasn’t decided yet.
A. had considered B. has been considering
C. considered D. is going to consider
19. —______ you ______ him around the museum yet? (2007江苏)
—Yes. We had a great time there.
A. Have ; shown B. Do ; show C. Had; shown D. Did; show
20. —Hi, Tracy，you look pale.
—I am tired. I _______ the living room all day.
A. painted B. had painted C. have been painting D. have painted
