…Present perfect…

Present perfect formula: [has/have + past participle]

We use the Present Perfect to say that an action happened at an unspecified time before now.

§ Ex: You have seen that movie many times.

§ People have traveled to the Moon.

§ A: Has there ever been a war in the United States?
B: Yes, there has been a war in the United States.

To have + Participle the verb

I have played
You have played
He has played
We have played
You have played
They have played

Us Present perfect

A) You can use the Present Perfect to describe your experience.

Ex- I have been to Germany.

I have never been to England.

B) We often use the Present Perfect to talk about change that has happened over a period of time.

Ex- You have grown since the last time I saw you.

C) We often use the Present Perfect to list the accomplishments of individuals and humanity.

Ex-Doctors have cured many deadly diseases.

D)We often use the Present Perfect to say that an action which we expected has not happened.

Ex- Susan hasn't mastered Japanese, but she can communicate.

Bill has still not arrived.

E) We also use the Present Perfect to talk about several different actions which have occurred in the past at different times.

Ex- We have had many major problems while working on this project.

Bibliography

http://www.englishpage.com/verbpage/presentperfect.html

http://www.englisch-hilfen.de/en/grammar/pres_perf.htm