happened
v. A1 Beginner US //ˈhæpənd// UK //hˈæpənd// hap·pened
v. to take place or occur, often by chance or without being planned.
v. to take place or occur as an event or circumstance. Intransitive — does not take a direct object.
Tell me exactly what happened last night.
The accident happened so quickly that none of the witnesses could remember the license plate number.
Historians still debate the specific sequence of events that led to the revolution, though most agree it happened much faster than contemporary observers expected.
Usage
The verb is intransitive and cannot be used in the passive voice.
Pitfall
The accident was happened yesterdayThe accident happened yesterday'Happen' is an intransitive verb and cannot be used in the passive voice (be + past participle).