Present Perfect
What is the perfect?
First of all, the perfect has nothing to do with perfection! It is possible to use English without using the perfect at all, and some languages have nothing like the English perfect. However, the perfect allows you to combine two different times in one idea.
For example,
The present perfect is a usage which many students have trouble with, because they cannot see how this is different to the past tense. The answer is often that the event is in the past, but it is important in the present (e.g. I have forgotten my passport, and my flight leaves in 15 minutes!) More importantly, the event in the past is still true now. If I say 'I have cleaned my shoes this morning', my use of the present perfect tells you that my shoes are still clean.
What is the grammatical construction of the perfect?
In English a verb has a meaning. However, our use of a part in front of the verb (called an auxiliary) tells us how to understand that meaning. (For example 'Did' before 'go' tells us the action was in the past; and 'will go' is in the future.) To identify a perfect, we use the auxiliary 'have', and use the past participle of the verb (the 'third part' - so with 'take, took, taken' 'taken' is the third part/past participle). 'Have' tells us that two times are involved in the idea that is being expressed, and tells us if we are looking at the past, present or future.
For example:
'I had taken' is in the past perfect tense, and refers to the earliest of two events in the past
'I have taken' is in the present perfect tense, and says that I took something in the past, and still have it in the present
'I will have taken' is in the future perfect tense, and says I have not taken something now, in the present, but I will in the future.
The present perfect and the past
Something which confuses many people is that the present perfect speaks of the past, but it is as the name says - a present tense. The reason for this is that the event started in the past, but it is still happening. When we talk about something in the past tense this often means that it has stopped happening, since otherwise we would use the present perfect. A good example of how the use of the present perfect contrasts with the past can be seen in the example below.
Think of a pet dog (Let's call him 'Spot')
It is much better to be able to say
'My dog, Spot, has lived for five years.'
than
' My dog, Spot, lived for five years.'
because in the second sentence, poor Spot has stopped living.
It is useful to describe things with the present perfect because this gives useful information.
For example:
Caller: Can I speak to Mr Jones, please?
Secretary: He has gone out.
Caller: Do you know when he will be back?
Because the secretary says 'has gone out', the caller knows that Mr Jones is still out, so he can prepare his next question to find out when Mr Jones will return. In this next example the secretary uses a simple past and makes the conversation more difficult
Caller: Can I speak to Mr Jones, please?
Secretary: He went out.
Caller: Well, where is he now?
Secretary: I don't know. He is still out.
Caller: Do you know when he will be back?
Past events, present importance
Because the present perfect connects the past and the present, we use it not just for things that happened in the past and are still true, but also for things that happened in the past and are important now.
For example:
Joe: There's a problem
Jane: What have you done?
Here, where Joe tells Jane that something is wrong, Jane is not interested in when that something went wrong, she is only interested in the fact that something is wrong now, so she asks Joe what he did to cause this problem, so that she can start to put it right.
For example:
Interviewer: Do you have any qualifications?
Interviewee: Yes, I have passed all the exams.
Here the interviewer wants to know if the interviewee is qualified. The interviewer is not interested when the interviewee otained the qualification - the important thing is that he did it.
Present perfect and time indicators
The confusing thing about the present perfect is that though it refers to an incident in the past, it is a present tense, because it is referring to the thing in the past now, in the present. In the same way that we cannot say 'I like dancing yesterday' you cannot say 'I have seen Fred yesterday'. Expressions of the present perfect have a time indicator of 'now', unless you say something that means the same, such as 'at present', 'today', 'this year' or 'for the past five years (up to now)'.
For example:
I went swimming yesterday. (An event in the past)
I have gone swimming today. (Present perfect, because it is still today)
For example:
Fred has worked hard on the project. (The project is not yet finished)
Fred worked hard on the project. (Either the project has finished, or Fred has.)
Notice the difference in these three sentences.
For example:
Fred arrived an hour ago. (This is an event in the past - an hour ago - so we use past tense. This sentence does not say if Fred is still here.)
Fred has been here for an hour. (The present perfect shows that Fred arrived an hour ago and is still here)
It has been cold over the last three days. (Present perfect, because it is still cold)
It was cold over the last three days. (But it is not cold now, so we use past tense)
Present perfect continuous
This is used when we want to describe something that happened in the recent past, and even though it has stopped, the results are still immediately obvious.
For example:
Carol's crying. She and Fred have been arguing.
Fred has a black eye. He and Carol have been arguing
For example:
Joe: You look angry.
Jane: I've been waiting for you for an hour!
