Mateo’s fingers flew across the keys. “Es de Don Alejandro.” He tried again. “La pluma es suya.” INCORRECT.

It practices the standard "Es de + [Owner]" formula perfectly.

In this scenario, we’re following , a notoriously disorganized but well-meaning college student, and Valeria , his incredibly observant roommate. The Setup: "The Lost Backpack"

The books are ours (nosotros). → _______________