To be true.... most of time we use the simple past to translate the present perfect.... "eu voltei ao parque hoje". Not many people use the present perfect. Example: "i have worked here since 2006" we'd say "trabalho aqui desde dois mil e seis"...not "tenho trabalhado aqui..."
Pretty sure this lesson is stone wrong. I am not a native Portuguese speaker, but I've studied it seriously for about ten years. The English translations for the present perfect just seem like utter nonsense to me.
Perhaps it is a difference between Brazilian and Iberian dialects? Any natives out there care to weigh in?