By Daniel, ESL Educator & Idiom Series Author
In 1635, an English poet named Francis Quarles published a book of poems called Emblemes. In it are two lines about hard work:
“Wee spend our mid-day sweat, or mid-night oyle;
Wee tyre the night in thought; the day in toyle.”
According to Gary Martin of The Phrase Finder, this is the first known printed mention of “the midnight oil.” Notice the verb: Quarles didn’t burn it. He spent it. Almost four hundred years later, we still use his image every time we say someone is burning the midnight oil.
What it means today
To burn the midnight oil means to work or study late into the night. It’s what students do before exams and what workers do before a big deadline.
“The report is due tomorrow, so I’ll be burning the midnight oil tonight.”
A lamp, a desk and a long night
Before electric light, people who wanted to read or write after dark needed a candle or an oil lamp. Lamp oil cost money, and every hour of light used some of it up. So if your lamp was still burning at midnight, everyone knew you were working hard.
The image of oil and study was common even before Quarles. Pascal Tréguer of Word Histories points out older English sayings, such as “to lose one’s oil” (to study or work for nothing) and “to smell of oil” (to show signs of too much careful study). Latin even had a single verb for working by lamplight at night, lucubrare, which gave English the rare word lucubration.
The verb changed over time. Quarles “spent” the oil, and Tréguer quotes the 18th-century poet William Shenstone, who “consum’d the midnight oil.” Today the fixed form is burn. When exactly burn took over isn’t clear from the sources I read.
Late nights that don’t count
Here’s the part dictionaries rarely spell out. Burn the midnight oil isn’t just about staying up late. It’s about staying up late to work, study or do something productive. The idiom carries a feeling of effort, and often a little pride or sympathy.
❌ “We burned the midnight oil at the party.”
✅ “We stayed up all night at the party.”
❌ “I burned the midnight oil watching my favorite series.”
✅ “I stayed up way too late watching my favorite series.”
Of course, people sometimes break this rule on purpose, as a joke: “I was burning the midnight oil… finishing level 40 of my game.” The humor works because everyone knows the phrase should mean serious work.
Grammar notes
- Keep “the midnight oil.” Not “burn midnight oil” or “burn the night oil.”
- It works in every tense. “She’s burning the midnight oil,” “I burned the midnight oil all week,” “You’ll have to burn the midnight oil.”
- It doesn’t need to be exactly midnight. Working until 11 p.m. or 3 a.m. both count.
- Tone: neutral and widely understood. You can use it in conversation, emails to coworkers and even in a news article.
Exam week
Aisha: Why are there five coffee cups on your desk?
Sam: Chemistry final on Friday. I’ve been burning the midnight oil all week.
Aisha: Is it working?
Sam: Ask me on Friday. Right now I can’t remember my own phone number.
Related idioms with a different focus
- pull an all-nighter: stay awake the whole night, usually to study or finish work. Stronger than burning the midnight oil.
- burn the candle at both ends: exhaust yourself by doing too much, often working early and going to bed late. This one is a warning, not praise.
- hit the books: start studying hard, at any time of day.
- night owl: a person who naturally likes to stay up late. It describes a habit, not hard work.
Your turn
Which sentence uses the idiom best?
a) “Carlos burned the midnight oil to finish his business plan before the meeting.”
b) “Carlos burned the midnight oil because he couldn’t fall asleep.”
Answer: a. In b, Carlos is awake, but he isn’t working, so “stayed up late” or “couldn’t sleep” fits better.
You might also like: Call It a Day, for when the work is finally finished.
A Note from Daniel
What moves me most about this idiom is the sense of continuity it brings. The student burning the midnight oil tonight is linked, through these words, to every scholar who once sat by lamplight centuries ago, all trying to finish before the night ended. The tools may be different now, but the feeling is the same. If you have a story about a night you burned the midnight oil, what you were working on, and whether it was worth it, I’d truly love to hear it.
Sources
- Martin, G. “Burning the midnight oil.” The Phrase Finder. phrases.org.uk
- Tréguer, P. “Meaning and origin of ‘to burn the midnight oil.’” Word Histories, 2016. wordhistories.net
- Cambridge Dictionary, entries: “burn the midnight oil,” “burn the candle at both ends.”
Every word carries a story. Stay curious. — Daniel