This document discusses three types of passive voice constructions in Spanish:
1) Process passive with "ser" which focuses on the ongoing action and uses "ser" plus the past participle (e.g. "El libro ha sido escrito por el autor").
2) State passive with "estar" which emphasizes the completed state and uses "estar" plus the past participle (e.g. "El libro está escrito").
3) Reflexive passive with "se" which is morphological active but has a passive meaning and uses the reflexive form of the verb (e.g. "Se alquilan pisos"). All verb tenses can be