The document discusses 16 tenses in English including:
- Present tense (simple present, present continuous)
- Past tense (simple past, past continuous)
- Future tense (simple future, future continuous)
- Perfect tenses (present perfect, past perfect, future perfect)
- Perfect continuous tenses (present perfect continuous, past perfect continuous, future perfect continuous)
- Past future tense
The tenses are explained through formulas, examples, and usage. Key points covered include conjugations, affirmative/negative/interrogative forms, and time expressions commonly used with each tense.