debi

In a sentence

• Debí terminar mi tarea antes de salir.

  I should have finished my homework before going out.

  Here, 'debí' is used to express a regret or missed obligation in the past.

• Cuando era niño, debí aprender a nadar.

  When I was a child, I should have learned to swim.

  In this sentence, 'debí' implies an unfulfilled necessity or suggestion in the past tense.

• Debí haber escuchado sus consejos.

  I should have listened to their advice.

  This usage of 'debí' conveys a past action that the speaker realizes would have been beneficial.