that all Spaniards have a double surname, the first being their father’s and the second their mother’s? When they have children, these take their father’s first surname as their first surname and the mother’s first surname as their second surname.
Example: If a man called Pedro García Torres and a woman called Mercedes Montero Fuentes marry and have two children called Javier and Lucía, then the children’s full names would be Javier García Montero and Lucía García Montero.
Easy, right? 😉
However, while old tradition has always given more importance to the father’s name, this is now changing in favour of the mother’s surname due to gender equality. 😊