No sé qué le pasa a Pedro. Está con nosotros y de pronto se ensimisma. Es como si no estuviera allí.I don't know what's the matter with Pedro. He's with us and suddenly loses himself in thought. It's like he's not even there.
Maribel dejó de atender a la conversación y se ensimismó en sus problemas.Maribel stopped listening to the conversation and became engrossed in her problems.
No lo entiendo. Mis hijos se ensimisman con esta serie. A mí me parece aburridísima.I don't get it. My kids become absorbed in this series. I think it's really boring.