The present perfect in English is used chiefly for completed past actions or events when it is understood that it is the present result of the events that is focused upon, rather than the moment of completion. No particular past time frame is specified for the action/event. When a past time frame (a point of time in the past, or period of time which ended in the past) is specified for the event, explicitly or implicitly, the simple past is used rather than the present perfect.