The document discusses the present perfect tense in English. It provides examples of its common uses, including for recent events without a specific time, personal experiences without a time, and actions that began in the past and continue to the present. It contrasts the present perfect tense with the simple past tense, noting that the present perfect does not use definite time expressions like "yesterday" while the simple past does.

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?