tinha acontecido

had happened

→ ter
phrase Rare #28,823
had happened Past perfect form of the verb phrase; used for an event that happened before another past action or point in time.
PO: Quando cheguei, já tinha acontecido tudo.
EN: When I arrived, everything had already happened.

Eu fiz o máximo possível para ter a certeza de que isso não tinha acontecido.

I did everything I could to make sure that hadn't happened.

Nós nos preocupamos se alguma coisa tinha acontecido.

We were worried that something might have happened.

Tive que me manter ocupado, assim não pensaria no que tinha acontecido.

I had to keep myself busy so I wouldn’t think about what had happened.

Pensei que algo terrível tinha acontecido com você.

I thought something terrible had happened to you.

— O Motorista de Táxi (2017)

Nós estávamos preocupados se tinha acontecido alguma coisa.

We were worried that something might have happened.

Tom sabia que algo tinha acontecido com Mary.

Tom knew that something had happened to Mary.

Eu pensei que algo tinha acontecido.

I thought something had happened.

— Braço de Diamante (1969)

Nós nos preocupamos se tinha acontecido alguma coisa.

We were worried that something might have happened.

Nunca tinha acontecido com você.

This had never happened to you before.

— Durante a Tormenta (2018)