Egyre jobb a tudásod my little duolingo, azt hittem csak az "én sétálok" formát fogadod el. So my little owl, I'm proud for you.
What's the difference between "sétálsz" and "maga sétál"?
Formality. "Maga sétál" can be used in formal situations (and it may even sound a bit... harsh? cold? not the most common formal way imo)
Köszönöm!