The document discusses the present perfect tense in English grammar. It provides examples of how and when the present perfect tense is used, including: 1) The present perfect is used for actions that started in the past and continue in the present. It is often used without a specific time period mentioned. 2) The present perfect can be used when the time period is recent or mentions "for" and "since" to indicate a duration of time or the point when the action started. 3) The present perfect tense is formed with the auxiliary verb "have" and the past participle of the main verb.