Present Perfect Tense

Present Perfect Tense
When is the present perfect tense used?
The Present Perfect Tense is used to describe an action that happened in the past, but has a connection to the present. The present perfect tense is also sometimes called the present perfect simple tense. The auxillary verb "have" is always used with the present perfect tense.
ThePresent Perfect Tense is used in the following situations:
There is a connection with the past.
The exact time of the action is not known.
"For" and "since" can be used to state the time of the action.
The action is not completed at the time of speaking/writing
The action happened before you expect.
The action has been repeated numerous time, and is expected to be repeated in the future.


Example
Past Present

I am not hungry. I have eaten at the school cafeteria.

I have learned English since 1956.

We have not known her for very long.

Have you been to China?

Has she finished collage?