The document discusses different tenses in English, including the present simple tense, present continuous tense, present perfect tense, and present perfect continuous tense. It provides the structure and examples for affirmative, negative, and interrogative sentences for each tense. The present simple tense is used to describe regular or habitual actions. The present continuous tense uses "be + verb+ing" to describe actions happening now. The present perfect tense uses "have/has + past participle" to describe completed actions. And the present perfect continuous tense uses "have/has been + verb+ing" to describe ongoing actions that began in the past.