Selasa, 24 Agustus 2010

Present Perfect Tense

How do we make the Present Perfect Tense?

The structure of the present perfect tense is:
subject + auxiliary verb + main verb
have past participle

Here are some examples of the present perfect tense:
subject auxiliary verb main verb
+ I have seen ET.
+ You have eaten mine.
- She has not been to Rome.
- We have not played football.
? Have you finished?
? Have they done it?
Contractions with the present perfect tense

When we use the present perfect tense in speaking, we usually contract the subject and auxiliary verb. We also sometimes do this when we write.
WSM Image
He's or he's??? Be careful! The 's contraction is used for the auxiliary verbs have and be. For example, "It's eaten" can mean:

* It has eaten. [present perfect tense, active voice]
* It is eaten. [present tense, passive voice]

It is usually clear from the context.

I have I've
You have You've
He has
She has
It has
John has
The car has He's
She's
It's
John's
The car's
We have We've
They have They've

Here are some examples:

* I've finished my work.
* John's seen ET.
* They've gone home.

How do we use the Present Perfect Tense?

This tense is called the present perfect tense. There is always a connection with the past and with the present. There are basically three uses for the present perfect tense:

1. experience
2. change
3. continuing situation

1. Present perfect tense for experience

We often use the present perfect tense to talk about experience from the past. We are not interested in when you did something. We only want to know if you did it:
I have seen ET.
He has lived in Bangkok.
Have you been there?
We have never eaten caviar.
past present future
!!!
The action or state was in the past. In my head, I have a memory now.
Connection with past: the event was in the past.
Connection with present: in my head, now, I have a memory of the event; I know something about the event; I have experience of it.
2. Present perfect tense for change

We also use the present perfect tense to talk about a change or new information:
I have bought a car.
past present future
- +
Last week I didn't have a car. Now I have a car.

John has broken his leg.
past present future
+ -
Yesterday John had a good leg. Now he has a bad leg.

Has the price gone up?
past present future
+ -
Was the price $1.50 yesterday? Is the price $1.70 today?

The police have arrested the killer.
past present future
- +
Yesterday the killer was free. Now he is in prison.
Connection with past: the past is the opposite of the present.
Connection with present: the present is the opposite of the past.

WSM Image
Americans do not use the present perfect tense so much as British speakers. Americans often use the past tense instead. An American might say "Did you have lunch?", where a British person would say "Have you had lunch?"
3. Present perfect tense for continuing situation

We often use the present perfect tense to talk about a continuing situation. This is a state that started in the past and continues in the present (and will probably continue into the future). This is a state (not an action). We usually use for or since with this structure.
I have worked here since June.
He has been ill for 2 days.
How long have you known Tara?
past present future


The situation started in the past. It continues up to now. (It will probably continue into the future.)
Connection with past: the situation started in the past.
Connection with present: the situation continues in the present.

For & Since with Present Perfect Tense

We often use for and since with the present perfect tense.

* We use for to talk about a period of time - 5 minutes, 2 weeks, 6 years.
* We use since to talk about a point in past time - 9 o'clock, 1st January, Monday.

for since
a period of time a point in past time
x------------
20 minutes 6.15pm
three days Monday
6 months January
4 years 1994
2 centuries 1800
a long time I left school
ever the beginning of time
etc etc

Here are some examples:

* I have been here for 20 minutes.
* I have been here since 9 o'clock.
* John hasn't called for 6 months.
* John hasn't called since February.
* He has worked in New York for a long time.
* He has worked in New York since he left school.

WSM Image
For can be used with all tenses. Since is usually used with perfect tenses only.

Tidak ada komentar: