The document discusses verb tenses and aspects in English. It explains the simple, progressive, and perfect forms of verbs in the present, past, and future tenses. Each tense can take the simple, progressive, or perfect aspect to indicate the timing or continuity of an action. For example, the present progressive describes an ongoing current action, while the past perfect describes an action completed before another past action. The document provides examples to illustrate how each tense-aspect combination is formed and used.