when "personne" means "persone" and when "no one"
@harribo - I think you mean: "Il n'y a personne". The n[e] is the negation of persons present.
i meant to write [person] in place of "persone"
there is a person -> Il y a une personne.
There is nobody -> Il y a personne
when there is not any article before "personne" it means nobody
Yes of course, we can say both ( I'm french speaker)
Actually, it is an easy one: if you have an article or a demonstrative adjective, then personne = person. "une personne, cette personne". Otherwise, personne= no one.