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´s auxiliaries are have and has 2 past participle of theverb 3 it´s assistant is did 4 it is used to talk about an action that has already ended 5 it is talking about experiences past simple assistant present perfect simple Present perfect simple verb past simple Present perfect simple auxiliaries