否定与疑问句由助动词have完成

常与这些副词或副词词组连用：

just, already, yet, ever, never,

in the past few years, recently, lately, today, nowadays, these days,

so far, up to present, up till now, by now, until now,

before (exactly when is not important) ,

since a past time, for a period

1. 属于现在时态，与和现在相关的时间状语连用。过去什么时间发生不知道或不重要，只强调对现在的影响或结果。如：“已经通过，有看到过，已经完成(具体什么时间没说)”等等。

●I have already written the letter but have not posted it yet.

●He hasn’t seen her lately（最近，非具体时间）.

●Have you seen her this morning? (“morning”is related to now，it is still morning.)If yes, what time exactly did you see her? 比较： Did you see her this moring? ("morning" is past.)

●I have just missed my stop!

●He has told me his name, but I have forgotten it..

 

2. 表示一个从过去某个时间开始，延续或经常性地重复到现在并可能持续下去的动作，常与表示一段时间的时间状语连用。如：so far, /up to present, /up till now, /by now（直到现在），/since(自从＋过去时间或过去时的从句), /for along time（很长时间），/in the past/last few years（在过去的几年里），/these days（目前）… …

●Has it stopped raining yet（=before now）?

● So far, I haven’t received a single letter from my brother.

●Scientists have found the way to cure the cancer BY NOW.

●He has lost his key for the second time so far since he came.

●It is the second time that he has lost the key to his bike.

● It’s the best meal I have ever had in the past year.

A.否定的状态(可以是短暂性动作)延续至现在，一般时：

I have not borrowed/bought any books from the library for many years since I left school.

He has not left the city for ten years since his retirement.

They haven't lent their cousin any money for ages since they had the row.

B.延续性动作表示一直持续到现在，可能还在进行中，因此用进行时。（不可用短暂性动词）

We have been waiting for him an hour but she hasn’t come.

c.f. We waited for more than an hour that day, then we left.

He has been painting the ceiling since yesterday(he is still painting or has just stopped painting). But he has only painted the floor. (He has finished painting the floor, but we don't know when.)

He has been running after her for 8 years.

I have been living/working in London since graduation.

也可用一般时: I have lived/worked there for many years.

有always不用进行时

I have always lived/worked here while my wife has applied for many jobs.

C.状态或结果动词，无进行时，用一般时：

I have known her since I came here.(不可用进行时)

The foreigner has been away for a long time.

D.非延续性动作重复发生用进行时。

. I’ve been borrowing books from the library for many years. I have borrowed hundreds of books and am always punctual to return the books, except for the last book I borrowed, which I have kept (been keeping) for months since the beginning of the year. I have not gone to the library for months.

He has been appearing in this club a lot lately.(最近常出现。重复。)

非延续性表某种感情色彩always用进行时

 Ø. I’ve (always)been wanting to see you for so many years.

 Ø. Who’s been telling you such nonsense all the time?

. They have been going out together a lot these days. They were seen to have a row last night though. That explains why they are not speaking to each other for the moment. But I don’t think they will spit up. It isn’t the first time they’ve quarrelled like this since they started dating with each other two years ago. Sometimes, they fought so fiercely that they seemed to be ending up separate but they always managed to get over and never really broke apart.

E.某些非延续性动词如非表示重复发生动作开始便终止的动词，无进行时，且不能与表示一段时间状语搭配。如appear，die, arrive，join，leave，go, refuse，fail，finish, buy, marry, divorce，awake，borrow，lend …

He has appeared in many films. (他演过很多电影。)

这类动词并非不能用现在完成时，而是不能与由for /since引导的表示有一段长度的时间状语连用。

但若是用在否定句中，非延续动词的现在完成时可以与表示一段时间的状语连用。

●She has gone away for a month.（误）

● She has been away for a month.（正）

 

● The man has died for two years.（误）

● The man has been dead for tow years.（正）

 

● How long have you bought the book?（误）

● How long have you kept the book?（正）

**注意since可以接过去确切时间或一般过去时的从句：

Ø. He has been here since 1980\ten years ago

Ø. It is ages since we dined together.

= we haven’t dined together for ages.

Ø. How long is it since I last saw him?

  　　　　　 现在完成时与一般过去时比较                           

**有明确的动作发生的时间用一般过去式。

如果发生时间不重要，强调的只是“已经发生”或者是“持续到现在”，用完成式。

Did he lose his key yesterday? Yes. He couldn’t get in.

But he has found it. (now)

Everyone helped/was helping him looking for it. It was found in the playgroud.

He remembered putting the key in his pocket and taking it downstairs. It must be that the key fell out when he was playing football.

He has fastened the string and attached the key to his belt (now). He did it immediately after the key was found.

The Chinese invented printing.

She is a scientist and has invented a few new printers.

**故事叙述中，第一句用完成时，后面恢复用过去式。

-Ow! I’ve burnt myself.

-How did you do that?

-I was picking up a hot dish, when Jim ran into me.

**几组对比：

He has gone to Shanghai. 他到上海去了。

He has been to Shanghai. 他去过上海。

 

She has gone. 她已走了。

She is gone. 她缺席了。（or 她死了）

 

The door has been closed. 门关上了。（动作）

The door is closed. 门是关着的。（状态）

 

  　　　　现在完成时与现在完成进行时比较         

现在完成时强调“次数、结果”，而完成进行时强调“动作的延续”。

He has been painting the room since yesterday, but has painted the ceiling only.

You have been reading the book all morning. How many pages have you read? Actually, he has read this book many times.

She’s been smoking a lot recently and has smoked packs of cigars this morning. She smoked dozens of packs of cigars yesterday.

完成进行时强调“动作的延续”,不可与次数连用。

We have been there many times（已经去过“完成”多次）

We always go to Ireland for holidays. （长期的习惯）

We are/have been going to Ireland a lot recently. (最近才有的习惯)

We have been going there for years.(重复这个习惯很多年了。)

Compare the following groups of sentences:

●  Jane has done a lot of work this morning. （It is still in the morning, and the result-a lot of work is emphasized. Jane might stop working soon.）

●  Jane did a lot of work this morning. （It is already at noon or in the afternoon or even later.）

●  Jane is doing a lot of work this morning. （It is still in the morning, and Jane is still busy working.）

 

We usually grow rice every year. But this year, we didn’t grow any.-- (growing season is "past".)

c.f. but this year, we haven’t grown any.--("this year" is still "now", we haven't grown "yet" and we may grow later)  

c.f. but this year, we are not growing any.-- ("this year" is still "going on" but we are not planning to grow any.)

 

She lived in Thailand for 3 years when her husband worked there.

She went back to China 5 years ago.

Now, She lives in her hometown in South China.

She’s been living (She’s lived) there for 5 years, since (she left Thailand in )2006.

But recently, she is living in Beijing, visiting her friends.