You have already learned several different uses of the verb ser. You will see that it can also be used to express the possession of things. Possession is expressed using the verb ser followed to the preposition de (like the expression of origin you just learned). The subject is the thing or object that is owned. The owner follows the verb and the preposition de.
| object owned + | ser de + | owner |
|---|---|---|
 El libro |
es de | Raul. |
| Los bolígrafos |
son de | Esteban. |
| La mochila |
es de | Susana. |
| El gato |
es de | José y Felipe.  |
| Los cuadernos |
son de | Alberto. |
