This document discusses the present perfect and past perfect tenses in English. It provides the structure, uses, examples, and interrogative forms for each tense. The present perfect uses have/has + past participle to refer to actions that began in the past but are still relevant to the present. The past perfect uses had + past participle to refer to two past actions where one occurred before the other. Examples are given for affirmative, negative, and interrogative sentences in both tenses. The document concludes with bibliographic references.