现在完成时用法

1 I have visited your school three weeks ago. I visited your school three weeks ago. 2 I have visited your school before. 3 I have written two letters last Sunday. I have written two letters.
He has gone to America.(去某地了，还没回来） He has been to America twice.
（去过某地，已经回来了）
Where have you been?
Where has she gone?
二、动词填空：
1. How longhave ____ you ____ lived (live) in the city? I _________ have lived (live) here for 15 years. did you move When ___ ____ (move) here? Icame ___ (come) here in 1987. has 2. How many times ____your unclebeen ___ (be) to the USA?
3. have / has been to 与have / has gone to 区别：
have / has been to : 去过某地，已经回来了，可 以和once, twice, never, ever连用 have /has gone to :去某地了（说话时某人已离 开此地，在去某地的路途上或已在某地)．
I have had this book for two weeks.
I bought this book two weeks ago.
It is two weeks since I bought this book. It is … since (过去时）….
这本书你借了多久了？
How long have you kept the book? 这辆自行车他已经买了三年了。 He has had this bike for three years. I’ve left Shanghai for 3 days. I’ve been away from Shanghai for 3 days. I left Shanghai 3 days ago. It is 3 days since I left Shanghai.
一般过去时和现在完成时的用法比较 因为一般过去时和现在完成时都表示过去的动 作或事情，所以同一件发生在过去的事或动作， 可用这两种时态来表示． He closed the windows. He has closed the windows. I bought a red car. I have bought a red car.
He __________ has been (be) there twice.
He _______ went (go) there to study math in 1945. He didn’t _____________(not return return) until 1951. went Last year, he _______ (go) there again.
1 Lin Ming has just turned off the light. 2 Have you ever ridden a horse? 3 Has Tom visited the Great Wall before?
B 表示动作或状态从过去某时开始，一直持续到 现在，并有可能延续下去。常与how long, for, since等表示一段的时间状语连用。
The Present Perfect Tense
现在完成时: 表示过去发生的动作对现在的影响。 １I live in Beijing. 2 I lived in Beijing. 我住在北京． 我住过北京．
3 I have lived in Beijing. 我一直住在北京．
Form: have / has + 过去分词 I have finished my homework. I haven’t finished my homework. Have you finished your homework? Yes, I have. No, I haven’t.
一般过去时和现在完成时的区别
1. 一般过去时能和过去时间状语连用，而现在完成时 不能。
I finished my work two hours ago. I have finished my work two hours ago.
2. 现在完成时和一般过去时都可以表示过去发生的动 作，但一般过去时只表示动作发生在过去这一事实， 它与现在没有关系；而现在完成时则表示动作发生在 过去，对现在仍有影响，有些动作一直延续到现在， 并且还可能延续下去。 He lived in Shanghai for five years. He has lived in Shanghai for five years.
三、翻译
1.你在这所学校已多久了？
How long ______________________this school? have you been atΒιβλιοθήκη 2. 我来这里已大约两年了。
been here for about I’ve ____________________________two years. 3.自从两年前，他就一直在这里。 has been here since He ________________________ two years ago.
2. 短暂性动词不能和表示一段时间的状语连用。 buy,borrow, leave, join, die, marry, come, go, begin, stop, lend, arrive I have bought this book for two weeks. 注意：从过去持续到现在的用法中，谓语动词通常 是延续性动词，如 live, stay, study, learn, know, teach, wear, be, keep（借）, have（买） 等
现在完成时用法：
A 表示动作在过去发生，且终止于过去，但结果对 现在仍有影响，既涉及过去又联系现在的时态。
already, just, ever, never, yet (已经，还）， now, before, recently, the last few years, in the past ten / few years
I wrote two letters last Sunday. when 不能和现在完成时连用
When have you bought the red car? When did you buy the red car?
A: I think the book is worth reading.
B: Have you borrowed it from our library?
1 He has lived here for 30 years. 2 How long have you studied English? 3 They’ve known each other since 1991.
for + 时间段 since + 时间点 / that for a long time, for a month, since 2 days ago, since yesterday, since then, up to now / until now, so far, these days
使用现在完成时注意事项：
1 现在完成时不能与表示过去的时间状语连用， 如 yesterday, just now, last night, two weeks ago, in 1992, when 引起的疑问句等， 但可以和包括现在在内的时间状语连用，如 today, now, this week/ term / year We have learned ten English songs this term.
A: Yes, I have.
B: When did you borrow it?
A: Two days ago.
B: So you have kept it for three days. B: When will you return it? A: I’ll return it as soon as I have read it / I finish it.