Relier Pairs characteristics of two topicVersion en ligne define which characteristics belong to the past simple or the present perfect simple par Silvia Pedraza 1 it is used to talk about an action that has already ended 2 it´s auxiliaries are have and has 3 it´s assistant is did 4 past participle of theverb 5 it is talking about experiences Present perfect simple verb present perfect simple Present perfect simple auxiliaries past simple past simple assistant