The "rule" has exceptions; for instance "mia madre" (my mother) has no article but "la mia mamma" (my mom) is preferred by dictionaries to "mia mamma", and "casa mia" (my home) is more common than "la mia casa". An interesting link is http://grammatica-italiana.dossier.net/grammatica-italiana-06.htm but it's in Italian so you'd need some translating :/
I am returning to a question posted five years ago, because I do not think it was answered. The sentence construction for 'I write my family's surname' is, in Italian: I write the surname OF my family. Therefore, what isn't the answer: Scrivo il congnome DI mia famiglia. The answer given by DL is: Scrivo il cognome DELLA mia famiglia. Doesn't della mean of the (di+la). The is not used in this sentence - it is a straight up of -- so what della not just di?
famiglia f (plural famiglie)
"famglia" is not a family member, thus article is required for the following Italian phrases.
• Dov'è la tua famiglia?
• [ Where is your family? ]
• Scrivo il cognome della
• [ I write my family's surname. ]
• [ I write the surname of my family. ]*
:) KK September 2019
Would A Cognome Be Considered A Type Of Nome In Italian, Like How A Surname Is A Type Of Name In English? If So, I Feel The "Cog" Part Here Isn't Necessary, As Surely The "Della Mia Famiglia" Part, Plus Context, Would Indicate It's A Surname? I've Never Heard Of A Family, Outside Royalty, Having One First Name, And Even Then Usually People Have Their Own Names But Would Change It When They Become King.