burn the midnight oil

Meaning

To work or study very late at night.

Examples

1. She burned the midnight oil to finish her thesis. US UK
2. We’ll have to burn the midnight oil if we want to meet the deadline. US UK
3. He has been burning the midnight oil all week for the exam. US UK

How to use it

The phrase comes from the time when people used oil lamps. Today people use it for working or studying late with great effort, not for parties. The verb burn can be burned or burnt in the past.

Common mistake

Not: We burned the midnight oil at the party until 3 a.m.
Say: We danced until 3 a.m. at the party. (Burn the midnight oil is for work or study.)