This document defines and describes the different types of tenses in English grammar. It discusses 12 tenses: present indefinite, present continuous, present perfect, present perfect continuous, past indefinite, past continuous, past perfect, past perfect continuous, future indefinite, future continuous, future perfect, and future perfect continuous. For each tense, it provides the structure, example sentences, and an explanation of when and how that tense is used. The document is intended to teach students the key aspects and uses of verb tenses in the English language.