It is rare to use the plural surname for referring to an entire family. One example is : family Popescu = familia Popescu = Popeștii . ( Popeștii au o mașină noua = the family Popescu have a new car ) family Damian = familia Damian = Damianii But I'd advise you to avoid using this kind of plurals. I am not sure if it's correct from a grammar point of view and it also sounds too informal. It can even sound a bit ironic , depending on context.