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Present Perfect Simple

2016-03-01 17:39 162 查看
have/has + past participle
Example: He has finished his homework.
have/has not + past participle
Example: I haven't finished my homework.
have/has ... + past participle?
Example: Have you finished your homework?
The principal uses of the present perfect are listed below.

To refer to a time period which is not yet finished (e.g. today, this month):

We've bought a new house this week. (an incomplete period)



To show that something happened in the past. We don't state when is happened:

I've lost my watch. Have you
seen it anywhere?

Note: If we give the time we must use the simple past:

I lost my watch yesterday. (not
I've lost my watch yesterday)

The following time expressions are often used: ever, never, always, up to now, so far.

This is the worst storm we've ever had. (at any point before now)

To talk about a situation which started in the past and usually continues after the time of speaking in the present:



He has lived here for six years. (He has lived here till now)

We use for with a lenght of time (e.g. for three weeks, for two days, for six years) and
since with a point in time (e.g. since 2010, since Wednesday, since nine o'clock, since I was five, since I moved here)

To talk about an action which occured at an unstated time in the past, provided that there is still a connection with the present:

I’ve collected all the documents that are needed for the house sale. (I have the documents now)

Note: If we give the time we must use the simple past:

I lost my watch yesterday. (not
I've lost my watch yesterday)

The following time expressions are often used: recently, just, already, and
yet with negatives or questions.

I've just arrived.

Have you done your homework yet?

Compare the use of the present perfect with the

past simple:

Present perfectPast simple
links the past with the present:

John has won several awards. (at some point before now and he may win more awards)
only talks about the past:

John won several awards in 2012.
does not talk about a specific time in the past:

Have you read the latest issue of the Magazine? (at some time before now)
states a specific past time, or the time is understood:

I read the latest issue of the Magazine when I was at home. (I'm not at home now and the reading is finished)
uses time expressions that show the time period is unfinished:

I haven't seen John this morning. (up to 12 noon, the morning isn't finished)
uses time expressions that show the time is finished:

I didn't see John this morning. (after 12 noon, last morning has finished)
Note the position of the following time expressions that occur with the present perfect:

between the auxiliary and main verb (e.g.
recently, already, always, ever, just, never):

I've already bought my ticket.

I’ve never met your brother.

Ever is generally used with questions or negatives:

Have you ever been to London?

after the main verb (e.g. all my life, every day, yet, before, for ages, for two weeks, since 2001, since I was ten etc.)

I haven't seen him for ages.

I’ve known John since I was ten.

if there is an object clause, the time expression comes at the end:

I've read this book every morning since then.

He hasn't ridden since he broke his arm.


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