Plural adjective of son, Latin filius filii given in the linguistic evolution towards Spanish son, as Word heritage, ( one of the rules of this evolution is that the " (f) " initial, followed by vowel, a word not monosyllabic tends to become " (h) " furnus, farina, or formica ). However subsidiary ( the son or the son or daughter ( filia ) ) It is a cultismo because it keeps the " (f) " Latin.