(-10-) "De" to indicate possession (Pablo's book = the book of Pablo; my parents' car = the car of my parents)
1. One can never use apostrophe 's in Spanish
(You can never say "Susana's padre" or "mis padres' casa")
2. Instead, one must use DE (of) and say "The thing of someone".
3. Pablo's book = el libro de Pablo
my friends' mother = la madre de mis amigos
Maria's classes = las clases de María