Question

oraciones afirmativas en presente perfecto

Answer 1

Te doy varios ejemplos y te recuerdo que el presente perfecto se forma con el verbo have/has + participio (V-ed o 3ª columna de los verbos irregulares): 

They have eaten the meal. 

She has written a letter.

We have played a football match.

I have decided to go.

He has bought a present for me.