This document provides an overview of how to use the present perfect tense in English. It explains that the present perfect is used to refer to an unspecified time before now. It gives examples of its use for experience, change over time, accomplishments, uncompleted actions, and multiple past actions. It clarifies how to use time expressions like "in the last year" with the present perfect. The key uses of the present perfect are to refer to experience, change, accomplishments, expectations, and multiple past actions without specifying a particular time.