現在完成時表示的動作發生在過去，以現在的時間為基點，但側重對現在產生的結果或造成的影響，與現在有關，其結構為“助動詞 have (has) + 過去分詞”;過去完成時則是壹個相對的時態，已過去時間為基點，它所表示的動作不僅發生在過去，更強調“過去的過去”，只有和過去某時或某動作相比較時，才用到它。
比較：I have learned 1000 English words so far.到目前為止我已經學會了 1000 個英語單詞。
I had learned 1000 English words till then.到那時為止我已經學會了 1000 個英語單詞。
— I'm sorry to keep you waiting. 對不起，讓妳久等了。
— Oh, not at all. I have been here only a few minutes.沒什麽，我只等了幾分鐘。(“等”的動作從過去某壹時間點持續到現在)
二、過去完成時與壹般過去時的區別
雖然這兩種時態都表示過去發生的動作或存在的狀態，但在使用時應註意以下幾點：
1. 時間狀語不同：過去完成時在時間上強調“過去的過去”;而壹般過去時只強調過去某壹特定的時間。
比較：They had arrived at the station by ten yesterday.
They arrived at the station at ten yesterday.
2. 在沒有明確的過去時間狀語作標誌時，謂語動詞動作發生的時間先後須依據上下文來判斷：先發生的用過去完成時，後發生的則用壹般過去時。
She was very happy. Her whole family were pleased with her, too.She had just won the first in the composition competition.
3. 當兩個或兩個以上接連發生的動作用 and 或 but 連接時，按時間順序，只需用壹般過去時來代替過去完成時;另外，在 before ， after ， as soon as 引導的從句中，由於這些連詞本身已經表示出時間的先後，因此也可以用過去時來代替過去完成時。
He entered the room, turned on the light and read an eveningpaper.
Ⅰ. MultipleChoices.
1.I lost the dictionary I ________.
A.have bought B.bought C.had bought D.had been bought
2.The train had gone when my brother _______ at the station.
A.have arrived B.arrived C.had arrived D.am arriving
3. Mary _______ of visiting her grandmother, but the bad weathermade her change her mind.
A.has thought B.thought C.had thought D.had been thought
4.------Did you meet Tom at the airport? ------No，he _______ by the time I______ there.
A.has left;got B.had left;arrived C.left;arrived D.left;had got
5.-------Why didn’t Tom attend the meeting yesterday? -------He __________ Beijing.
A.has gone to B.had gone to C.went to D.had been to
6.-------I _______ to come to help you. ------But you didn’t come.
A.have meant B.had meant C.meant D.will mean
7.Finally one of my friends _______ by Beijing University，for which she ___ five timA.were admitted; had tried B.was admitted; had tried C.were admitted; has tried D.was admitted; tried
8.------I have bought you the books you want. ------Oh，good，I _______ afraid you had forgotten.
A.was B.am C.had been D.have been
9.We _________ four thousand new words by the end of last year.
A.had learned B.have learned C.learned D.will have learned
10.Helen _______her keys in theoffice so she had to wait until her husband ______home.
A.has left;comes B.left;had come C.had left;came D.had left;would come
11. My father _________ to the hospital when I hurried home.
A. had gone B. went C. had been taken D. had been sent
12. ----- Jim, ________ you _________ your homework?
----- Yes, of course, but I ________ it late bed time.
A. do do; finished B. did do; had finished C. have done; hadfinished D. have done; finished
13. You ____ football after school. Why not go home and do yourhomework first?
A. always played B. are always playing C. have always played D.have always been playing
es
14. Eversince Picasso’s painting went on exhibit, there ____ large crowds at the museumevery day.
A. is B. has been C. have been D. had been
15. ---What do you think of my suggestion? --- Sorry. What’s that?I _____ about something else.
A. was thinking B. thought C. am thinking D. had thought
Ⅱ. Fill in theblanks according to the meanings of the sentences by using tenses of the verbs.
1. How many English songs ___________ she __________ (learn) bythe end of last month?、
2. Hardly _______ I ______ (get) on the bus when it started tomove
3. He __________________(read) the book before he was ten yearsold.
4. She said she ___________________ (see) the film before.
5. Our English teacher _________________ (teach) English inGuangxi for ten years before he came to No.113 Middle School.
6. By the end of last month, they _________________(complete)thebridge .
7. No sooner ________ I _______ (go) out than he came to see me.
89. The classroom _______________ (clean) before we ___________(get) there yesterday.
10. ________ the boy ___________ (finish) his homework before yousaw him?
11. When we got to the station, the train _____________ already_____________. (leave)
12. The book __________ by the end of last month. (finish)
13. When I got back to the shop , my bag _________________ (take)away by someone else.
14. When I arrived at the cinema, the film _________________ (be)on for ten minutes.
15. ---What’s that terrible noise?
---The neighbors ______ (prepare) for a party.
16. The mayor of Beijingsays that all construction work for the Beijing Olympics ______ ( complete) by2006.
17. The teacher, with 6 girls and 8 boys of her class, ______(visit) a museum when the earthquake struck.
18. ---Mr. Johnson didn’t turn up at the meeting yesterdaymorning, did he?
--- No. We __________ (wait) till twelve o’clock. A whole morningwas wasted.
19. ---Why haven’t you asked her to come here?
---She _______ (do) an important experiment when I found her andshe ________ (not, finish) it.
答案：
Keys:
Ⅰ. 1-5 CBCBB 6-10BBAAC 11-15. DDBCA
Ⅱ. 1. had learnt2. had got 3. had read 4. had seen 5. had taught 6. had completed 7. had gone8. had gone 9. had been cleaned, got 10. Had finished 11. had left 12. had beenfinished 13. had been taken 14. had been on 15. are preparing 16. will havebeen completed 17. was visiting 18. were waiting 19. was doing, hasn’t finished