The document provides instruction on using the past perfect and past perfect continuous tenses in English. It defines the past perfect as an action that occurred before another past action, and the past perfect continuous as a continuing past action that ended at a certain point in the past. Examples and exercises are included to illustrate forming sentences in these tenses and when to use each one. Key points covered include using adverbs like "already" or "for" with the past perfect, and how the past perfect continuous focuses on duration while the past perfect is a single action.