This document provides instruction on using the present perfect tense in English. It explains that the present perfect tense is used to talk about experiences or actions that started in the past and continue in the present. It also notes that the present perfect tense can be used to discuss actions that had results in the present. The document then gives examples and formulas for forming affirmative, negative, and interrogative sentences in the present perfect tense. Finally, it discusses using "for" with a period of time and "since" with a specific time in present perfect sentences. Two exercises are included for practice using "for" and "since."