You use the perfect tense when, in English, you would say that something has happened. So, if you wanted to say: ‘You have been to the hairdresser,' 'she has eaten all the biscuits’ or anything else ...
The contrastive use of the present perfect and the preterite in the Spanish-speaking world differs from region to region. For the Andean region, however, where Spanish is in contact with Quechua, it ...