You’ve seen it everywhere: colour vs. color, centre vs. center, travelling vs. traveling. It’s not random—and it’s not worth memorizing word by word. Most of the time, British and American spelling follows a handful of repeatable patterns. Spot the pattern once, and you can spell dozens of words correctly without thinking twice.
British vs. American Spelling
British English vs. American English often spells the same word differently. Below is a practical list of common British vs. American spelling differences.
The 5 Core Spelling Rules (UK → US)
| Rule (UK → US) | Examples (UK) | Examples (US) |
|---|---|---|
| -our → -or | colour, humour, favourite | color, humor, favorite |
| -re → -er | centre, theatre, litre | center, theater, liter |
| -ise → -ize (common in US) | organise, realise, apologise | organize, realize, apologize |
| -yse → -yze | analyse, paralyse | analyze, paralyze |
| Double L → single L (often in US) | travelled, cancelled, travelling | traveled, canceled, traveling |
Common British vs. American Spelling Pairs
When possible, the examples below use the same sentence structure so the spelling difference is easy to spot.
CENTRE vs. CENTER
- UK: The shopping centre is open until 9 p.m.
- US: The shopping center is open until 9 p.m.
THEATRE vs. THEATER
- UK: Let’s go to the theatre tonight.
- US: Let’s go to the theater tonight.
COLOUR vs. COLOR
- UK: What’s your favorite colour?
- US: What’s your favorite color?
FAVOURITE vs. FAVORITE
- UK: That’s my favourite song.
- US: That’s my favorite song.
HONOUR vs. HONOR
- UK: It’s an honour to meet you.
- US: It’s an honor to meet you.
LABOUR vs. LABOR
- UK: The party’s Labour voters turned out early.
- US: The report focuses on labor costs.
ARMOUR vs. ARMOR
- UK: The police should be protected by body armour.
- US: The vehicle has extra armor.
BEHAVIOUR vs. BEHAVIOR
- UK: I must apologise for my outrageous behaviour.
- US: The school has strict rules about behavior.
ODOUR vs. ODOR
- UK: The kitchen had a strange odour.
- US: The kitchen had a strange odor.
FLAVOUR vs. FLAVOR
- UK: This soup has a rich flavour.
- US: This soup has a rich flavor.
- UK: She wore a grey coat.
- US: She wore a gray coat.
TRAVELLING vs. TRAVELING
- UK: We’re travelling to France next week.
- US: We’re traveling to France next week.
TRAVELLED vs. TRAVELED
- UK: He travelled across the country by train.
- US: He traveled across the country by train.
CANCELLED vs. CANCELED
- UK: All flights have been cancelled because of fog.
- US: All flights have been canceled because of fog.
CATALOGUE vs. CATALOG
- UK: I ordered it from the catalogue.
- US: I ordered it from the catalog.
DIALOGUE vs. DIALOG
- UK: Most plays are written in dialogue.
- US: Click “OK” in the dialog box.
AGEING vs. AGING
- UK: He’s caring for his ageing parents.
- US: He’s caring for his aging parents.
- UK: I’d like to make an enquiry about train times.
- US: The police opened an inquiry into the incident.
- UK: She walked towards the exit.
- US: She walked toward the exit.
AEROPLANE vs. AIRPLANE
- UK: The aeroplane landed safely.
- US: The airplane landed safely.
SULPHUR vs. SULFUR
- UK: Sulphur dioxide can irritate the lungs.
- US: Sulfur dioxide can irritate the lungs.
PLOUGH vs. PLOW
- UK: The farmer repaired the plough.
- US: The farmer repaired the plow.
JEWELLERY vs. JEWELRY
- UK: The police recovered the stolen jewellery.
- US: The police recovered the stolen jewelry.
ANAEMIA vs. ANEMIA
- UK: The doctor ran tests for anaemia.
- US: The doctor ran tests for anemia.
SOMBRE vs. SOMBER
- UK: He wore a sombre black suit.
- US: He wore a somber black suit.
LITRE vs. LITER
- UK: The bottle holds one litre.
- US: The bottle holds one liter.
ENROL vs. ENROLL
- UK: Is it too late to enrol in the course?
- US: Is it too late to enroll in the course?
WOOLLEN vs. WOOLEN
- UK: He was sweating in his thick woollen suit.
- US: He was sweating in his thick woolen suit.
MOUSTACHE vs. MUSTACHE
- UK: He’s trying to grow a moustache.
- US: He’s trying to grow a mustache.
APPETISER vs. APPETIZER
- UK: We served olives as an appetiser.
- US: We served olives as an appetizer.
AXE vs. AX
- UK: Be careful with that sharp axe.
- US: Be careful with that sharp ax.
Commonly Confused Pairs
PRACTISE vs. PRACTICE
- UK (verb): He wants to practise his English every day.
- UK/US (noun): It takes a lot of practice to play the piano well.
- US (verb): You should practice your pronunciation aloud.
LICENCE vs. LICENSE
- UK: licence (noun) / license (verb)
- US: license for noun and verb
- UK (noun): You need a fishing licence.
- UK (verb): The council will license new operators.
- US: The officer asked to see his driver’s license.
NOUGHT vs. NAUGHT
- Nought is commonly used for 0 (especially in British usage and in scores: “two-nil”).
- Naught is more old-fashioned/literary and means nothing.
- The score was two–nought.
- All his threats came to naught.
Last Updated on March 3, 2026
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