ero sicura che

I was sure that

→ essere
phrase Rare #38,866
I was sure that “Sicura” is the feminine form; use “sicuro” when the speaker is masculine.
IT: Ero sicura che sarebbe arrivato in tempo.
EN: I was sure he would arrive on time.

Ero sicura che fossero ancora qui!

I was sure they were still here!

— Tre uomini in fuga (1966)

Ero sicura che sarebbe tornato e che avrei fatto quello che voleva.

I was sure he would come back and that I would do what he wanted.

— Donne sull'orlo di una crisi di nervi (1988)

Ero sicura che fosse di Mei.

I was sure it was Mei's.

— Il mio vicino Totoro (1988)

Non ero sicura che mi credesse così ingenua, ma avrei provato.

I wasn’t sure he thought I was that naive, but I would have tried.

Ero sicura che non me ne sarebbero serviti neanche lontanamente cinque.

I was sure I wouldn’t need anywhere near five.

E non ero sicura che foste bloccati.

And I wasn’t sure you were stuck.