estaba segura de que

was sure that

→ estar
phrase Rare #43,517
was sure that Used by a female speaker; a male speaker would say “estaba seguro de que.”
SP: Estaba segura de que todo saldría bien.
EN: I was sure that everything would turn out well.

Estaba segura de que eras tú.

I was sure it was you.

Estaba segura de que sería feliz con él.

She was sure she would be happy with him.

— Stalker (1979)

Estaba segura de que volvería y que yo haría lo que él me pidiera.

I was sure that he would return and that I would do whatever he asked of me.

— Mujeres al borde de un ataque de nervios (1988)

Estaba segura de que iba a aprobar el examen final.

I was sure I was going to pass the final exam.

Estaba segura de que tenías a alguien, una zorra, como la de Peppe.

I was sure you had someone, a slut, like Peppe's.

— Perfectos desconocidos (2016)