八下英语Unit8现在完成时语法课件
6.不变： put-put-put , run-ran-run, comecame-come, become-became-become, readread-read, cut-cut-cut,
1.写出下列动词的过去式和过去分词 am/is ____ _____ are_____ _______ see _____ ______ do ______ ______ go ______ ______ give ______ ______ take _____ ______ know ______ ______ speak _____ _____ write ______ ______ put _____ _____ run _____ _______ come _____ _____ sing ______ ______ forget _____ ______ become_____ ______
I came to China three years ago.
come to China been in China
three years ago
now
She has bought the computer for two years.
had
buy
have/has had
I have left Shanghai for 3 days.
What have they done?
用括号中所给的动词的适当形式完成下列句子。 1. The boy _h_a_s___just _s_e_e_n_(see) my father. 2. __H_a_v_e_ you __fo_u__n_d (find) your watch yet? 3. We _h_a_v_e__already r_e_t_u_rn__ed(return) the book.
注意点三、非延续性动词与现在完成时 短暂性动词可以用于现在完成时，但不能与时间 段连用。这些动词是：become, begin, buy, borrow, arrive, come, die, fall, finish, get to know, go, join, leave, marry等。 I have borrowed this book. I have borrowed this book for three days. （错）
1.have you __e_v_e_r___ been to Beijing? No, _n_e_v_e_r.
2.I have _j_u_s_t__ finished my work. 3.I have finished my work_a__lr_e_a_d_y. 4.Have you finished your work__y_e_t__? 5.She has taught English _f_o_r__ 10 years. 6.He has worked in the factory _s_in_c_e__1 year ago. 7.I have heard of the story _b_e_f_o_r_e_.
他已入团两年了。
The man has been dead for several years. The man has died for several years. 这个人已经死了几年了。
( (
√×))
1.I have borrowed the book for 2 weeks.
A
B
C ( B kept )
been away from Shanghai
leave
have/has been away
I have borrowed the dictionary since 3 days ago .
kept
borrow
have/has kept
The film has begun for 10 minutes.
I have kept this book for three days.
非延续性动词要转化成延续性动词才能和时间段 连用。
瞬间动词在完成时中不和表示一段时间的状语连 用。 如: 我来中国3年了。
I have come to China for three years.
I have been in China for three years.
( ×)
(√ )
They have been here for two days. They have come here for two days. 他们来这儿已经两天了。
((√×))
He has joined the League member for two years. ( ×)
√ He has been a League member for two years. ( )
been on
begin
have/has been on
His dog has died for two years .
been dead
die have/has been dead
I have bought a new dictionary for a week. I have had a new dictionary for a week. 我买一本新词典已有一星期了。
5. ---Has Tom taught you English? --Yes, he h_a_s__ta_u__g_ht(teach) us English for a year. 6. I _h_a_v_e_n_’t__fi_n_is_h_e(ndot finish) my homework yet.
Yes, he has. No, he hasn’t. /Not yet. 2. I have never been to Beijing before.(一般
问句)
Have you ever been to Beijing before? 3. They have learned around five units.(提问)
2.过去已经开始，持续到现在的动作或状态
I have lived here for three years.
I have lived here since 2000/three years ago.
现在完成时动词构成have /h源自s+v 过去分词(及物动词)
助动词
否定
haven’t hasn’t
since two hours ago.
have/has gone to have/has been to have/has been in
• have/has gone to:已经去了或在途中，还没 有返回；
• have/has been to:曾今去过某地，现在已经 回来了,后面可接表示“次数”的状语;
3.以重读闭音节结尾，末尾只有一个辅音字 母的 双写＋ed. 如：plan, stop, drop, fit(适合), prefer(更喜欢), travel
4.以辅音字母＋y，结尾，变y为i＋ed try, study, carry, hurry, cry, worry,copy
不规则变化：
5.特殊:am/is/are-was/were-been, seesaw-seen, do-did-done, go-went-gone, take-took-taken, give-gave-given, know-knew-known, speak-spokespoken, write-wrote-written, singsang-sung , forget-forgot-forgotten
Can you help me? 7. My father _h_a_s_r_e_a_d__ (read) the book twice. 8. How long __h_a_v_e_ you _k_n_o_w_n_(know) him? 9. Sheh_a_s__w_r_it_t_e(nwrite) the book for two years. 10. These children h_a_v_e__s_ta_y_e_d(stay) in the park
3.关键词： just, yet; since, for; ever, never; already, before
按要求进行句型转换
1. He has already finished his homework.(一 般问句，并作肯定、否定回答) Has he finished his homework yet ?
疑问
Have you……? Has he……?
答语 Yes, 主语+have/has. No, 主语+haven’t/hasn’t
过去分词的构成
规则变化：
1.+ed work, plant, call
2.e+d live, change, like, love, agree, save, hate, move, arrive, skate, hope,
现在完成时
现在完成时
moved here havienb2r0e0a0kfast
构成have/has + 过去分词
I’mI sntoiltl hliuvenghreyrenow
1.过去发生的动作对现在造成的影响或结果。
I have just cleaned my clothes. 我刚洗过衣服。 （“洗衣服”是发生在过去的动作，对现在造成的结 果是“衣服干净了”） I have just had my breakfast. (对现在的影响：不饿)
2.The film has begun for 5 minutes.( B been on)
ABC
3. 这辆自行车我买了两年了。
1.写出下列动词的过去式和过去分词 am/is ____ _____ are_____ _______ see _____ ______ do ______ ______ go ______ ______ give ______ ______ take _____ ______ know ______ ______ speak _____ _____ write ______ ______ put _____ _____ run _____ _______ come _____ _____ sing ______ ______ forget _____ ______ become_____ ______
I came to China three years ago.
come to China been in China
three years ago
now
She has bought the computer for two years.
had
buy
have/has had
I have left Shanghai for 3 days.
What have they done?
用括号中所给的动词的适当形式完成下列句子。 1. The boy _h_a_s___just _s_e_e_n_(see) my father. 2. __H_a_v_e_ you __fo_u__n_d (find) your watch yet? 3. We _h_a_v_e__already r_e_t_u_rn__ed(return) the book.
注意点三、非延续性动词与现在完成时 短暂性动词可以用于现在完成时，但不能与时间 段连用。这些动词是：become, begin, buy, borrow, arrive, come, die, fall, finish, get to know, go, join, leave, marry等。 I have borrowed this book. I have borrowed this book for three days. （错）
1.have you __e_v_e_r___ been to Beijing? No, _n_e_v_e_r.
2.I have _j_u_s_t__ finished my work. 3.I have finished my work_a__lr_e_a_d_y. 4.Have you finished your work__y_e_t__? 5.She has taught English _f_o_r__ 10 years. 6.He has worked in the factory _s_in_c_e__1 year ago. 7.I have heard of the story _b_e_f_o_r_e_.
他已入团两年了。
The man has been dead for several years. The man has died for several years. 这个人已经死了几年了。
( (
√×))
1.I have borrowed the book for 2 weeks.
A
B
C ( B kept )
been away from Shanghai
leave
have/has been away
I have borrowed the dictionary since 3 days ago .
kept
borrow
have/has kept
The film has begun for 10 minutes.
I have kept this book for three days.
非延续性动词要转化成延续性动词才能和时间段 连用。
瞬间动词在完成时中不和表示一段时间的状语连 用。 如: 我来中国3年了。
I have come to China for three years.
I have been in China for three years.
( ×)
(√ )
They have been here for two days. They have come here for two days. 他们来这儿已经两天了。
((√×))
He has joined the League member for two years. ( ×)
√ He has been a League member for two years. ( )
been on
begin
have/has been on
His dog has died for two years .
been dead
die have/has been dead
I have bought a new dictionary for a week. I have had a new dictionary for a week. 我买一本新词典已有一星期了。
5. ---Has Tom taught you English? --Yes, he h_a_s__ta_u__g_ht(teach) us English for a year. 6. I _h_a_v_e_n_’t__fi_n_is_h_e(ndot finish) my homework yet.
Yes, he has. No, he hasn’t. /Not yet. 2. I have never been to Beijing before.(一般
问句)
Have you ever been to Beijing before? 3. They have learned around five units.(提问)
2.过去已经开始，持续到现在的动作或状态
I have lived here for three years.
I have lived here since 2000/three years ago.
现在完成时动词构成have /h源自s+v 过去分词(及物动词)
助动词
否定
haven’t hasn’t
since two hours ago.
have/has gone to have/has been to have/has been in
• have/has gone to:已经去了或在途中，还没 有返回；
• have/has been to:曾今去过某地，现在已经 回来了,后面可接表示“次数”的状语;
3.以重读闭音节结尾，末尾只有一个辅音字 母的 双写＋ed. 如：plan, stop, drop, fit(适合), prefer(更喜欢), travel
4.以辅音字母＋y，结尾，变y为i＋ed try, study, carry, hurry, cry, worry,copy
不规则变化：
5.特殊:am/is/are-was/were-been, seesaw-seen, do-did-done, go-went-gone, take-took-taken, give-gave-given, know-knew-known, speak-spokespoken, write-wrote-written, singsang-sung , forget-forgot-forgotten
Can you help me? 7. My father _h_a_s_r_e_a_d__ (read) the book twice. 8. How long __h_a_v_e_ you _k_n_o_w_n_(know) him? 9. Sheh_a_s__w_r_it_t_e(nwrite) the book for two years. 10. These children h_a_v_e__s_ta_y_e_d(stay) in the park
3.关键词： just, yet; since, for; ever, never; already, before
按要求进行句型转换
1. He has already finished his homework.(一 般问句，并作肯定、否定回答) Has he finished his homework yet ?
疑问
Have you……? Has he……?
答语 Yes, 主语+have/has. No, 主语+haven’t/hasn’t
过去分词的构成
规则变化：
1.+ed work, plant, call
2.e+d live, change, like, love, agree, save, hate, move, arrive, skate, hope,
现在完成时
现在完成时
moved here havienb2r0e0a0kfast
构成have/has + 过去分词
I’mI sntoiltl hliuvenghreyrenow
1.过去发生的动作对现在造成的影响或结果。
I have just cleaned my clothes. 我刚洗过衣服。 （“洗衣服”是发生在过去的动作，对现在造成的结 果是“衣服干净了”） I have just had my breakfast. (对现在的影响：不饿)
2.The film has begun for 5 minutes.( B been on)
ABC
3. 这辆自行车我买了两年了。
合集下载
八年级下英语现在完成时态课件
• They haven’t bought any new house since they moved to Shanghai.
• She hasn’t bought any new clothes for a year.
三.几个相近短语的区别：
have/has gone to:已经去了或在途中，还没有 返回；(去了未回来)
• Have you met him before? • 你以前见过他吗？ • My brother met her in the street two
days ago. • 我哥哥两天前在街上遇到了她。 • I have just had breakfast. • 我刚吃过早餐。 • She had breakfast just now. • 她刚吃了早餐。
最近
in the past/last +时间段 过去的…
by now, so far, up to now, till now 迄今
once, twice…
一次…
all/in one’s life
某人一生
（1）already
肯定句: “己经”
I’ve already had breakfast. (更常见) = I’ve had breakfast already.
I have finished my homework. I have not finished my homework. Have you finished your homework? Yes, I have./No, I haven’t.
She has been to Europe. She hasn’t been to Europe. Has she been to Europe? Yes, she has./No, she hasn’t.
• She hasn’t bought any new clothes for a year.
三.几个相近短语的区别：
have/has gone to:已经去了或在途中，还没有 返回；(去了未回来)
• Have you met him before? • 你以前见过他吗？ • My brother met her in the street two
days ago. • 我哥哥两天前在街上遇到了她。 • I have just had breakfast. • 我刚吃过早餐。 • She had breakfast just now. • 她刚吃了早餐。
最近
in the past/last +时间段 过去的…
by now, so far, up to now, till now 迄今
once, twice…
一次…
all/in one’s life
某人一生
（1）already
肯定句: “己经”
I’ve already had breakfast. (更常见) = I’ve had breakfast already.
I have finished my homework. I have not finished my homework. Have you finished your homework? Yes, I have./No, I haven’t.
She has been to Europe. She hasn’t been to Europe. Has she been to Europe? Yes, she has./No, she hasn’t.
Unit8现在完成时课件人教版八年级英语下册
1.找
2. 变
3.去
4.加
What have they haddaomeal at a restaurant since they left school?
特殊疑问句
特殊疑问句= 特殊疑问词+ 一般疑问句
what who when which why what color what time
代替事物、事情 代替人 代替时间 代替事物，表选择 代替原因 代替颜色 代替时间点
2、before 表示之前发生的事情，放在句末。 I have been。
现在完成时的时间状语：
3、yet 放在否定句和一般疑问句句末。
just, before, recently,still, lately, never, ever, twice, on several occasions, in the past/weeks/months/years, till now.
6、ever
表示经常的或习惯性的动作，常与表示频率的时间状语连用。 放在 have/has后面，动词后面
例句:Their debts have grown ever larger. 他们的债务不断增加。
根据句意，完成下列句子 1，They _h_a_v_e_g_o_n_e (go) to the Beihu Park this year.
2，以不发音的e结尾
+d
3, 辅音字母+y结尾
改y为i+ed
4，以重读闭音节结尾， 双写该辅音字母
末尾只有一个辅音字母
+ed
示例
work---worked visit---visited
live---lived hope---hoped
人教版初中英语八年级下册 Unit8 SectionA 现在完成时态专项讲解 课件
Amy has worked
at this school for 9 years.
7
past now
She began to learn She has learned English in 2014. English for 3 years.
用法2：表示从过去某一时刻开始一直持续到 现在的动作或状态，还有可能继续下去，常和 For或since引导的时间状语连用。
for + 时间段 since+时间点
for 6 years/2 months
since 6 years ago
since she left Jiujiang
10
一、用for和since填空。
__f_o_r__three years __f_o_r___two seasons _s_in_c_e__three hours ___f_o_r __a long time
有时，也用在疑问句中表示惊讶。
Have you done your homework already ?
Yet:
用于否定句中表‘’尚未，还‘’。 用于疑问句中表‘’已经‘’。放 在句尾。
I haven’t been to Pairs yet .
Have you read the text yet ? 4
A. one year B. three weeks ago
12
6. Miss Withe has owned this hotel for__A____.
A. over ten years B. six years ago
7. They’ve lived here for___B___.
A. last winter
at this school for 9 years.
7
past now
She began to learn She has learned English in 2014. English for 3 years.
用法2：表示从过去某一时刻开始一直持续到 现在的动作或状态，还有可能继续下去，常和 For或since引导的时间状语连用。
for + 时间段 since+时间点
for 6 years/2 months
since 6 years ago
since she left Jiujiang
10
一、用for和since填空。
__f_o_r__three years __f_o_r___two seasons _s_in_c_e__three hours ___f_o_r __a long time
有时，也用在疑问句中表示惊讶。
Have you done your homework already ?
Yet:
用于否定句中表‘’尚未，还‘’。 用于疑问句中表‘’已经‘’。放 在句尾。
I haven’t been to Pairs yet .
Have you read the text yet ? 4
A. one year B. three weeks ago
12
6. Miss Withe has owned this hotel for__A____.
A. over ten years B. six years ago
7. They’ve lived here for___B___.
A. last winter
人教版英语 八年级下册 Unit8 SectionA 现在完成时态专项讲解 课件
2
2、谓语结构：have/has +V--过分
肯定：sb+have/has+V-过分
否定：sb+haven't/hasn't+V-过分
一疑：Have/Has+sb+V-过分?
肯答：Yes,sb have/has. 否答：No,sb haven't/hasn't.
• 注：have/has做助动词，后接动词过去分词，与人称 代 词 搭 配 可 缩 写 成 ： 've/'s(I've=I have;they've=they have)。haven't=havenot hasn't=has not，其中have 用于非三单人称，has用于第三人称单数。
• have/has做行为动词表拥有，不能缩写。 • 能区别he's= he has/he is • she's=she has/she is it's=it has/it is
3
例句：
1、I have already read Little Women?
否定句：I haven't read Little Women yet.
一疑句：Have you read Little Women yet?
肯答： Yes,I have.
否答： No,I haven't.
2、She's lived here since 2008.
否定句：She hasn't lived here since 2008.
一疑句：Has she lived here since 2008?
3.放置put--put--put
2、谓语结构：have/has +V--过分
肯定：sb+have/has+V-过分
否定：sb+haven't/hasn't+V-过分
一疑：Have/Has+sb+V-过分?
肯答：Yes,sb have/has. 否答：No,sb haven't/hasn't.
• 注：have/has做助动词，后接动词过去分词，与人称 代 词 搭 配 可 缩 写 成 ： 've/'s(I've=I have;they've=they have)。haven't=havenot hasn't=has not，其中have 用于非三单人称，has用于第三人称单数。
• have/has做行为动词表拥有，不能缩写。 • 能区别he's= he has/he is • she's=she has/she is it's=it has/it is
3
例句：
1、I have already read Little Women?
否定句：I haven't read Little Women yet.
一疑句：Have you read Little Women yet?
肯答： Yes,I have.
否答： No,I haven't.
2、She's lived here since 2008.
否定句：She hasn't lived here since 2008.
一疑句：Has she lived here since 2008?
3.放置put--put--put
Unit8 SectionA 现在完成时态专项讲解 课件 人教版英语八年级下册
1）一般过去时表示过去某时发生的动作或单纯
叙述过去的事情，
强调动作；现在完成时为过去发生的，强调过去
的事情对现在的影响，
强调的是影响。
2）一般过去时常与具体的时间状语连用，而现
在完成时通常与模糊的时间状语连用，或无时间
状语。
一般过去时的时间状语：yesterday, last week
，…ago, in1980, in October, just now等，皆
A. for B. with C. to D. of
3. —Zoos are good for animals.
— No, I _____ you.
A. disagree to
B. agree to
C. disagree with D. agree with
4.All of them ____ people ____ the environment.
9
选择填空
1.Nature is like a(n) ____ textbook for us all.
A. alive B. lively C. live D. living
2. The government has provided lots of donation
____ the homeless people so far.
1
Review the important words and structures we learned in this unit. Distinguish The Past Tense and The Present Perfect Tense.
2
基础知识复习
Review words and expressions in Unit 8.
八年级英语下册 Unit 8 Have you packed yet？Grammar课件 鲁教版五四制
现在完成时的三种基本用法： 1、未完成用法。表示动作或状态开 始于过去，一直延续到现在，可能继 续发展，也可能刚刚结束。 He has been in the army for ten years. I have studied English since 1980. He has lived here all his life. a. be, live, study 都是延续性动词。
---Hi, Tracy, you look tired. --- I am tired. I ___ the living room all day. A. painted B. had painted C. have been painting D. have painted
When I was at college I ___ three foreign languages, but I ___ all except a few words of each. A. spoke; had forgotten B. spoke; have forgotten C. had spoken; had forgotten D. had spoken; have forgotten “但都忘了”是现在的情况，要用现 在完成时，强调结果。
We have known each other since 1997. （现在完成时把过去的动作和现在联系起来并着眼 于现在） She has been to Beijing.
(现在已不在北京，从结果上和现在联系起来） She has been in Beijing for two years. （现在仍在北京，从时间上和现在联系起来）
---___ the sports meet might be put off. ---Yes, it all depends on the weather. A. I’ve been told B. I’ve told C. I’m told D.I told “被告知”是过去的事，对现在的影 响 是“我已知道”。
初中英语 人教版八年级下册UNIT8语法：现在完成时1课件
5
现在完成时用法2
1. She is a doctor. She began to work when she was 20. Now, She is 28. She ________ for eight years.
2. They went to London last Saturday. Today is Saturday. They _________ (stay) in London since last Saturday.
3.She had breakfast in the morning. Now, she is not hungry because she_____
3
现在完成时用法1
1. I saw this film last week. Now, I know this film because I have seen it before .
12
现在完成时标志词
just “刚刚 ”用在陈述句中,放在句中。 I have just bought a novel. She has just had dinner.
before “以前”用在完成时中，放在句末。 Ｉhave never read this kind of books before. Have you been to Shanghai before?
规则动词：与过去时变化相同。 (1) 一般+-ed work---worked---worked
(2) 以“ e ”结尾, + - d 。 live---lived ---lived
(3) “辅音字母 + y” 结尾，y 变 i, + -ed。 cry---cried---cried
现在完成时用法2
1. She is a doctor. She began to work when she was 20. Now, She is 28. She ________ for eight years.
2. They went to London last Saturday. Today is Saturday. They _________ (stay) in London since last Saturday.
3.She had breakfast in the morning. Now, she is not hungry because she_____
3
现在完成时用法1
1. I saw this film last week. Now, I know this film because I have seen it before .
12
现在完成时标志词
just “刚刚 ”用在陈述句中,放在句中。 I have just bought a novel. She has just had dinner.
before “以前”用在完成时中，放在句末。 Ｉhave never read this kind of books before. Have you been to Shanghai before?
规则动词：与过去时变化相同。 (1) 一般+-ed work---worked---worked
(2) 以“ e ”结尾, + - d 。 live---lived ---lived
(3) “辅音字母 + y” 结尾，y 变 i, + -ed。 cry---cried---cried
人教八下Unit8_语法专项课件(现在完成时1)(共20张PPT)
现在完成时三大用法
用法2
2) 表示过去发生的动作,强调结果或对现在 的影响。
Someone has broken the window. (窗户现在是坏的)
I have just cleaned my hands.
(手是干净的)
现在完成时三大用法
用法3
3) 表示从过去开始并持续到现在的动作或 状态。
初中英语人教版八年级下册
Unit8
语法专项课件 （现在完成时1）
现在完成时结构
肯定句：主语 + have/ has + 过去分词+... I have finished my homework.
结构
否定句:主语+haven’t ( have not) +过去分词… 主语+hasn’t ( has not ) +过去分词...
不规则变化
B.过去分词与过去式形式不一样
take—took—taken
speak —spoke—spoken
sing—sang—sung
drive—drove—driven
be—was/were—been
go—went—gone
过去式、过去分词
不规则变化
C.过去分词、过去式与动词原形一样
cut—cut—cut
put —put—put
let—let—let read—read—arning
started learning English 3 years 2012
have learned English
2015
I started learning English in 2012. （一般过去时）
She has learned English for 5 years. He has lived in Beijing since he was born .
初中英语 人教八下 unit8 语法--现在完成时用法讲解及训练(共26张ppt)
in your project.
A. learned
B. are learning
C. have learned
D. learn
「品味」句意：嗨，伙计们，请写三个你们上学期在课题当中学到 的事实。时间状语last term“上个学期”提示定语从句中的谓语 动词用一般过去时。故选A。
3. (19黄冈) —Have you watched the new movie, Joe?
Grammar
**现在完成时**
• ？什么是时态？ A. 时态是英语独有的一种语法情况。在汉语中，不论什么时候发 生的动作，
都是用同一动词，而在英语中，不同时间里发生的动作，动词要 用不同
的形式，这就是时态。、
如： He played computer games yesterday.
Look! He is listening to the net class.
• B: yes, I _have____. Once I _got____ a ticket and had to pay $ 50.
• A: __Have___ you ever _seen____ a body-building competition? (see)
• B: Yes, I __have___. I __will seen___ the National Championship this year.
品味中考
1. (19·河北)I ______ an invitation to the concert. I can’t wait to go.
A. receive B. will receive C. was receiving D. have received 2. (19 ·扬州) Hi, guys, please write three facts you __ last term in your project.
unit8 现在完成时 课件
--- Sorry, I don’t know. 8. My father _____ (read) the novel twice. 9. ___English?
注意: 现在完成时与一般过去时的用法比较 现在完成时表示过去的动作对现在造成的影响；一般过去时表示动 作发生的时间在过去。现在完成时属于现在时态范围，因此，不能 和表示过去的时间状语连用。 如：yesterday, last night, two weeks ago等 试比较： The plane has arrived . 飞机已经到了。（说明现在的情况：飞机 在这儿） The plane arrived a quarter ago. 飞机是一刻钟以前来的。（强 调动作发生的时间在过去）
take-took-taken
come-came-come
run- ran – run
become-became-become
表示过去发生的某一动作对现在造成的影响或结果,例如 I have just cleaned my clothes. 我刚洗过衣服。 （“洗衣服”是发生在过去的动作，对现在造成的结果是 “衣服干净了”）
that already. ⑤ I’ve just finished my homework. ⑥ He has not come yet.
用括号中所给的动词的适当形式完成下列句子: 1. Mary _______(lose) her pen. 2. ______ you ______ (find) your watch yet? 3. ---Are you thirsty? ---No, I ______ just _______ (have) some orange. 4. We ________already ______ (return) the book. 5. ______ they _____ (build) a new school in the village? 6. I ______(not finish) my homework yet. Can you help me? 7. The door is open. Who ______ (open) it? Do you know?
注意: 现在完成时与一般过去时的用法比较 现在完成时表示过去的动作对现在造成的影响；一般过去时表示动 作发生的时间在过去。现在完成时属于现在时态范围，因此，不能 和表示过去的时间状语连用。 如：yesterday, last night, two weeks ago等 试比较： The plane has arrived . 飞机已经到了。（说明现在的情况：飞机 在这儿） The plane arrived a quarter ago. 飞机是一刻钟以前来的。（强 调动作发生的时间在过去）
take-took-taken
come-came-come
run- ran – run
become-became-become
表示过去发生的某一动作对现在造成的影响或结果,例如 I have just cleaned my clothes. 我刚洗过衣服。 （“洗衣服”是发生在过去的动作，对现在造成的结果是 “衣服干净了”）
that already. ⑤ I’ve just finished my homework. ⑥ He has not come yet.
用括号中所给的动词的适当形式完成下列句子: 1. Mary _______(lose) her pen. 2. ______ you ______ (find) your watch yet? 3. ---Are you thirsty? ---No, I ______ just _______ (have) some orange. 4. We ________already ______ (return) the book. 5. ______ they _____ (build) a new school in the village? 6. I ______(not finish) my homework yet. Can you help me? 7. The door is open. Who ______ (open) it? Do you know?