The document discusses the present perfect tense in English. It explains that the present perfect is used to talk about past events with an indefinite time frame or that have relevance to the present. Examples are given of using the present perfect to talk about life experiences, news, and duration of states from the past continuing to the present using "for" or starting points using "since". Common time expressions that can be used with the present perfect like "just", "already", and "yet" are also defined.