leave on

leave on — phrasal verb

  • leave onbase form
  • leaves on3rd person singular
  • leaving on-ing form
  • left onpast simple

1. to let a machine, light, or other device keep working by not switching it off

1.phrasal verbtransitiveA2
Definition

to let a machine, light, or other device keep working by not switching it off

Example

Omar left the television on while he cooked dinner in the kitchen.

pattern: leave + [device] + on

Ritu always leaves her computer on so she can check messages right away.

habitual: always leaves + [device] + on

Common collocations
  • leave the lights on
  • leave the TV on
  • leave the computer on
  • leave the oven on
Synonyms
  • keep running

    more explicit about the continuous operation of a machine

  • not turn off

    literal paraphrase; less idiomatic but clearer for learners

Antonyms
  • turn off

    opposite action — stopping the device from working

  • switch off

    same as 'turn off', used especially for lights and electronics

Grammar Patterns

leave + noun/pronoun + on

Usage Note

Frequently used with devices that consume electricity or fuel (lights, TV, oven, computer, engine). The object must go between 'leave' and 'on' — never 'leave on + object'.

Common Mistakes

Please leave on the light before you go.
Please leave the light on before you go.
The object of 'leave on' must go between the verb and the particle.

2. to continue wearing a piece of clothing rather than taking it off your body

2.phrasal verbtransitiveA2
Definition

to continue wearing a piece of clothing rather than taking it off your body

Example

Kasia left her hat on during the whole outdoor ceremony.

pattern: leave + [garment] + on

Asher left his glasses on when he jumped into the swimming pool.

Common collocations
  • leave your coat on
  • leave your shoes on
  • leave your hat on
  • leave your jacket on
Synonyms
  • keep on

    more general; can be used with any garment in any context

  • not take off

    literal paraphrase; less idiomatic but helpful for understanding

Antonyms
  • take off

    opposite action — removing a garment from the body

Grammar Patterns

leave + article of clothing + on

Usage Note

Often used in situations where removing the garment would be normal (e.g., coming indoors, sitting at a table). The object goes between 'leave' and 'on'.

Common Mistakes

He left on his jacket when he went inside the restaurant.
He left his jacket on when he went inside the restaurant.
The garment must go between 'leave' and 'on', not after 'on'.