The document discusses the present perfect simple and continuous tenses. It provides examples of how each is used to talk about finished and unfinished actions. The present perfect simple is used for experiences, actions that started in the past and continue now, and finished actions with an unspecified time. The present perfect continuous is used for actions that started in the past and continue now, and very recently finished actions whose results can still be seen. It also lists common time expressions used with each tense.