had happened
It would never have occurred to me.
Si hubiera tenido cuidado, entonces el terrible accidente no hubiera ocurrido.
If he had been careful, then the terrible accident would not have happened.
Ahora se comporta como si nada hubiera ocurrido.
Now he behaves as if nothing had happened.
No puedo imaginar qué hubiera ocurrido si no llego estar ahí ¿Cómo está ahora?
I can’t imagine what would have happened if I hadn’t been there. How is he/she doing now?
— Do You Thing (2001)
Tom negó que hubiera ocurrido.
Tom denied that it had happened.
Si ese accidente hubiera ocurrido en una ciudad, habría causado un desastre.
If that accident had happened in a city, it would have caused a disaster.
No lo va a recordar, como si nunca hubiera ocurrido.
He won't remember it, as if it never happened.
— El maquinista (2004)
Tom hizo como si no hubiera ocurrido nada.
Tom acted as if nothing had happened.
Jugaban con las almohadas como si nada hubiera ocurrido.
They played with the pillows as if nothing had happened.