To indicate activities
Completed in immediate past but giving the feel of present.
The washer man has washed the clothes.
Subject + has/have + v3rd form + object
They have played the game.
He has played the game.
subject + has/have + not + v3rd form + object
She has not sung a song
I have not solved the sum.
has/have +subject + v3rd form + object
Have you posted the letter?
Has he stolen the pen?