happen
v.v. to take place or occur, often by chance or without being planned.
v. to take place or occur as an event; to be the result of a specific set of circumstances. Intransitive — it does not take a direct object.
Accidents happen when people are tired.
The meeting is scheduled to happen at three o'clock in the main conference room.
While we can predict certain outcomes based on historical data, it is impossible to know exactly what will happen when the new policy is finally implemented.
From Middle English happenen, hapnen, augmented from Middle English happen (“to come to pass, happen”), perhaps from Old English hæppan (“to move accidentally, slip”) and/or from Old Norse happa, heppa, from Proto-Germanic *hampijaną (“to fit in, be fitting”). Equivalent to hap (“a chance, occurrence, byfall”) + -en (verbal suffix).
The verb is intransitive and cannot be used in the passive voice.
The accident was happened yesterday.The accident happened yesterday.Happen is an intransitive verb and cannot be used in the passive voice.