Passive Voice: ser, ficar, and estar
European Portuguese forms the passive with ser + past participle for events, estar + past participle for resultant states, and ficar + past participle for a change leading to a state.
PortuStories Editorial
European Portuguese Grammar Guide
The standard passive voice uses ser + past participle. The participle agrees in gender and number with the subject.
A carta foi escrita pelo diretor.
The letter was written by the director.
Passive event with ser.
A janela estava aberta.
The window was open.
Resultant state with estar.
Ela ficou surpreendida com a notícia.
She was surprised by the news.
ficar = became/was left in a state.
The reflexive passive (se + verb) is also very common in EP, especially for impersonal or unspecified agents.
Vendem-se apartamentos neste prédio.
Apartments are sold in this building.
If the focus is on the action and who did it, use ser + participle. If the focus is on the resulting state, use estar. If emphasising the change of state, use ficar.
From a PortuStories Story
O edifício foi construído em 1920 e ainda está bem conservado.
The building was built in 1920 and is still in good condition.