This document discusses the past perfect and past perfect continuous tenses in English grammar. It defines the past perfect tense as indicating an action that was completed in the past. The formula is subject + had + past participle. Examples of positive, negative, and interrogative sentences in the past perfect tense are provided. The past perfect continuous tense indicates an action that started in the past and continued up to another point in the past, stressing duration. Its formula is subject + had + been + present participle. Examples of sentences in the past perfect continuous tense are also given.