eu estivera

had been

i ʃ t i v ɛ ɾ ɐ → estar
estiv to be + era pluperfect
verb · 1st-person singular / 3rd-person singular, pluperfect tense Rare #41,942
had been Literary or formal past perfect form; everyday speech usually uses “tinha estado.”
PO: Quando cheguei, ela já estivera aqui.
EN: When I arrived, she had already been here.
Conjugation of estar
Indicative pluperfect
SingularPlural
First estivera —
Third estivera estiveram

Katrina tinha trabalhado muito durante os poucos dias em que eu estivera fora.

Katrina had worked a lot during the few days I’d been away.

Ele já estivera preso.

He had already been in prison.

— Não Conte a Ninguém (2006)

Na semana passada ele viu um velho amigo que estivera anos sem ver.

Last week he saw an old friend he hadn't seen in years.