debieron

Debieron is the third-person plural form of the Spanish verb deber in the pretérito perfecto simple (past simple). It corresponds to "they/you all owed" or "they/you all should have" depending on the context and the accompanying infinitive or complement. The form is used with subjects such as ellos, ellas or ustedes.

Grammatically, debieron is a regular form of an -er verb in the past tense, following the standard conjugation pattern for deber in the pretérito: debí, debiste, debió, debimos, debisteis, debieron. It can express obligation in the past, as in debieron terminar el proyecto (they were supposed to finish the project), or a moral or social expectation about past actions. It also occurs in constructions that convey deduction or probability about a past event when combined with haber, as in debieron haber llegado (they must have arrived).

Usage notes and nuances:

- Debieron indicates a completed or assumed obligation in the past, often aligning with what was expected or demanded at that time.

- In negative form, no debieron puede mean they should not have or they must not have, depending on context and intonation.

- Some speakers also use the version debieron de haber llegado, which adds a modal nuance of probability or deduction, though debieron haber llegado is widely accepted.

Etymology and related forms:

Deber derives from the Latin debēre, meaning to owe or to owe obligation. Related forms include debo (I owe), debes (you owe), debe (he/she owes), debemos, deben, and imperfect forms such as debía, debías, debía, debíamos, debían.

In sum, debieron is a past tense form used to express past obligations, expectations, or deductions about events in the past, with nuances shaped by context and accompanying elements.