Understanding the customary way Italians named their children will help you research your family.
If you know your Italian ancestors' traditional naming patterns, you can use the bambini's names to guess the parents' and grandparents' identities. The first son usually received the name of his father's father; the second son, his mother's father; and the third son, his father. The first daughter was named after the father's mother; the second daughter, after the mother's mother; and the third daughter, after the mother.
Italians also used necronymics — naming a baby after a deceased sibling — so if you see two or more Anna Francescas in the same family, don't assume it's a mistake. Because parents chose names to honor older generations, they would pass a moniker onto their next-born if the first child given that name died.
From the June 2005 Family Tree Magazine