This is the 13033rd most frequent Spanish word.
planificaban
"They planned" or "they were planning."
In this context, 'planificaban' is used to indicate a past action in progress, specifically the act of planning a holiday trip.
Ellos planificaban un viaje para las vacaciones.
They were planning a trip for the holidays.
Here, 'planificábamos' is used to describe an ongoing and thoughtful action in the past regarding strategic planning.
Nosotros planificábamos la estrategia para el proyecto.
We were planning the strategy for the project.
In this sentence, 'planificaban' conveys a past intention or action being considered or prepared.