This document discusses the present perfect simple and present perfect continuous tenses in English. The present perfect simple is used to describe life experiences, events that have already happened or just finished, connections between past events and the present, and durations or quantities. The present perfect continuous emphasizes actions that started in the past and continue in the present, repeated actions, and actions that have just finished. It is used with time expressions like "for" and "since" to describe the duration of an ongoing action.