The document discusses the use of present perfect tense in English. It provides examples of actions that stopped recently, actions that began in the past and continue to the present, and actions or experiences in the past without a specific time mentioned. Signal words that can be used with the present perfect include already, just, never, ever, yet, so far, and for. The present perfect is formed with have/has plus the past participle of the main verb, and it can be used in the affirmative, negative, or interrogative form.