The document discusses the present perfect tense. It explains that the present perfect is used to describe past events or experiences without a specific time reference. It notes words like "just", "ever", "never", "already", and "yet" are used with the present perfect tense. The document also outlines how to form the present perfect tense affirmatively, interrogatively, and negatively using the helping verbs "have" or "has" plus the past participle form of the main verb.