The document discusses the present perfect tense in English. It explains the form of the present perfect tense using have/has + past participle. It outlines three main uses of the present perfect tense: 1) to describe recent events without a definite time, 2) to express personal experiences without a definite time, and 3) to express actions that started in the past and continue to the present. It contrasts the present perfect tense with the past simple tense and provides examples to illustrate the difference between the two tenses.

1. Present Perfect Tense The autumn has already arrived How do you know?

9. Present Perfect Tense Have you walked along a riverside similar to the one on the photograph? When did you do it?