I got lost — can I exit and come back in?
'Perso' — PER-so. Short, clipped 'e'; the double meaning (lost/confused) is common in speech.
Ask a station attendant when you have exited through the wrong gate and need to re-enter without paying again. This happens often in large interchange stations.
'Mi sono perso' uses the reflexive passato prossimo with 'essere'. 'Perso' is the irregular past participle of 'perdere' (to lose). 'Rientrare' (to re-enter) is the prefix 'ri-' added to 'entrare', a productive pattern in Italian: fare → rifare, aprire → riaprire.
Ho preso la direzione sbagliata.
I took the wrong direction.
Explains what went wrong without asking for help directly.
Posso usare lo stesso biglietto?
Can I use the same ticket?
Confirms whether re-entry is free or requires a new ticket.
Sono uscito per sbaglio.
I exited by mistake.
Simple explanation to the station guard.
Italian metro attendants are generally helpful with confused tourists. Showing the ticket and explaining calmly almost always resolves the situation. Staying calm and polite goes a long way — raising your voice will make things worse.