Phrasal verb
jam on
Definition
phrasal verb. to press something down quickly and with a lot of force, usually the brakes of a car.
phrasal verb. to apply something—typically vehicle brakes—suddenly and forcefully; often used to describe an emergency or reflexive action.
Examples
“I had to jam on the brakes when the cat ran out.”
“The driver ahead of me jammed on his brakes for no reason, nearly causing a pile-up.”
“As the train approached the blocked crossing, the engineer jammed on the emergency brakes, sending a screeching sound through the valley.”
Examples
simple
“I had to jam on the brakes when the cat ran out.”
contextual
“The driver ahead of me jammed on his brakes for no reason, nearly causing a pile-up.”
complex
“As the train approached the blocked crossing, the engineer jammed on the emergency brakes, sending a screeching sound through the valley.”
Usage
almost exclusively used with 'the brakes' as the object.
Teaching tip
teach this as a collocation with 'brakes'; it conveys more urgency and suddenness than 'hit the brakes' or 'apply the brakes'.
Pitfall
He jammed the brakes on.
He jammed on the brakes.
while technically possible to separate, 'jam on' is almost always used as a unit before the object 'the brakes'.
Phrasal verb
Particles
on
Separability
optional
Pattern
jam + on + object
Synonyms
Antonyms
Grammar
Scan code
englishreference.com/q/jam-on