We form Present Perfect in the following way: have + verb 3
Now let us see how and why we use this tense:
- We use it If an event is still in progress:
I have worked for a company for 10 years
- When we talk about past events without mentioning the time. In this case we talk about experiences.
I have eaten Mexican food
I have visited Paris three times
As you see, it is not the time which matters here but the results, the fact that you have done something and that you have experience about it.
- We can also use it if an action has an effect on the present:
I have washed the car
In this case, we can say that the car is clean – as the result of the action preceded the moment of speech.
Now let meintroduce some time expressions connected to Present Perfect. They are since and for. Since refers to time and for refers to time duration. It is also important to know that they both have end position in the sentence:
I have worked here since 2002
I have worked here for 10 years
Future Perfect does not have so much to do with the present as Present Perfect does. This tense has a role in the future. Let us see how we form it first:
will have + verb 3
It is used when an action will be completed by a specific time in the future.
The workers will have finished the building by next month
Which means that the progress of building is still an ongoing event but it will be finished soon. nd there are some time expressions which often come with this tense:
Time expressions: by + time / by + action
If we want to express an action after BY, we need to use Simple Present there:
By the time you are done with your work, the film will have started.