This is the 3371st most frequent Spanish word.
deber
"Deber" means "to must," "to have to," or "to owe," depending on the context.
Here, 'debo' (I must) is used to express obligation.
Debo estudiar para el examen mañana.
I must study for the test tomorrow.
In this sentence, 'debería' (should) expresses a recommendation.
Ella debería ser más cuidadosa.
She should be more careful.
Here, 'deben' (owe) is used to indicate gratitude or a causal relationship.