This document provides a summary of the present perfect tense in English grammar. It states that the present perfect is formed with has/have plus the past participle of the verb for affirmative statements and questions, and has/have plus not for negative statements.

1. afirmative Present perfect Has: he,she,it Have: I,you,we,they + verb(past participle)

2. negative has/have + not + verb(past participle)

3. question has/have first + verb(past participle)