Translation guide
The English word 'collision' covers physical crashes between objects, vehicles, or people, as well as abstract clashes of ideas, schedules, or interests. Japanese uses different words depending on what is colliding and how severe it is.
car collision
schedule conflict
Describing a physical crash between cars, trains, ships, or other objects, often in accidents.
The most general word for a collision between vehicles or objects. Can also be used metaphorically.
There was a car collision on the highway.
Specifically a rear-end collision.
A violent crash or smash-up, often used in dramatic contexts.
When ideas, opinions, or personalities conflict strongly.
When two events or appointments happen at the same time.
Accidentally bumping into a person while walking.
Scientific term for particles or objects hitting each other.
衝突 is more formal and often used for serious accidents or abstract clashes. ぶつかる is casual and physical, like bumping into someone or something.
The cars collided. (formal/accident)
列車の正面衝突が起きた。
A head-on collision of trains occurred.
信号待ちで追突された。
I was rear-ended while waiting at a traffic light.
トラックが壁に激突した。
The truck smashed into the wall.
Also used for clashes of opinions or personalities.
Their opinions often collide.
I clashed with my boss and quit the company.
Confrontation or opposition, often between groups or ideas.
The two political parties are in conflict.
Literally 'to overlap', used for schedule conflicts.
The meeting times collided (overlapped).
From English 'batting', meaning schedules clash. Casual.
My plans collided (overlapped).
I bumped into someone.
More formal, used for people colliding but less common in casual speech.
The pedestrians collided with each other.
Standard term in physics.
particle collision experiment
自転車で壁にぶつかった。
I bumped into the wall with my bicycle. (casual)
For lightly bumping into someone in a crowd, ぶつかる is natural. 衝突 would sound overly dramatic.