PRESENT PERFECT SIMPLE RULES IT IS USED TO TALK ABOUT AN EVENT / A SITUATION THAT:  TOOK PLACE IN THE PAST AND IS PART OF ONE’S EXPERIENCE: EX: They have been to China!  HAS JUST FINISHED AT THE TIME OF SPEAKING: EX: I have just read the lastest book from Harry Potter  IS FINISHED AT THE TIME OF SPEAKING OR HAS COMPLETELY FINISHED BUT IS IMPORTANT NOW: EX: I see, you have bought a new laptop!