he present perfect is formed from the present tense of the verb have and the past participle of a verb:
The present perfect continuous is formed with have/has been and the -ing form of the verb:
6. •I have seen that movie twenty times.
•I think I have met him once before.
•There have been many earthquakes in California.
•People have traveled to the Moon.
•People have not traveled to Mars.
•Have you read the book yet?
7. There are basically three uses for the present
perfect tense:
-experience
-change
-continuing situation