The document discusses different verb tenses in English categorized by time frame and aspect. There are 12 possible verb tenses formed from combining the present, past, and future time frames with the simple, continuous, perfect, and perfect continuous aspects. The tenses are used to express actions, events, or situations that occur in the present, past, or future time periods. Examples of how to form affirmative, negative, and interrogative sentences for each tense are also provided.