accadesse

happened, would happen

→ accadere
accad happen, occur + esse imperfect subjunctive (io/tu/lui/lei)
verb · singular, imperfect tense Rare #40,881
happened, would happen Used in a subordinate clause after expressions such as “I expected” or “I allowed.”
IT: Non pensavo che accadesse così in fretta.
EN: I didn’t think it would happen so soon.
Conjugation of accadere
Subjunctive imperfect
accadesse

Come avete potuto permettere che accadesse questo?

How could you let this happen?

Come hai potuto permettere che questo accadesse?

How could you let this happen?

Ho lasciato che accadesse.

I let it happen.

— L'ultimo imperatore (1987)

Come ha potuto permettere che accadesse questo?

How could he let this happen?