One of the most confusing topics in Italian is when to use essere o avere in the passato prossimo. We know that passato prossimo is the most common way to express a recent past.
You might have seen sono andato and ho mangiato. Why do they change?
Think of the verbs. To go and to eat. I go (I am moving somewhere). I eat (I accomplish an action). When you talk about movement, change of state, reflexive verbs you use ESSERE.
When you refer to other actions (eat, create, do) then you will use AVERE.
Io sono uscito I went out
Io sono arrivato I arrived
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