The document summarizes different tenses in English including the present perfect, present perfect progressive, past perfect, and past perfect progressive tenses. It provides examples of sentences using each tense and identifies which clauses use the different verb forms to express earlier and later events. Key uses of each tense are outlined such as the present perfect to talk about indefinite or repeated events, the past perfect to talk about events that occurred before other past events, and the inclusion of time expressions like "for" and "since" with certain tenses.