British vs American Spelling
B1 · IntermediateSpelling RulesColour vs. color, centre vs. center, travelled vs. traveled — two spelling systems, same language.
What you'll learn
- British -our often becomes American -or: colour/color, favourite/favorite, honour/honor
- British -re often becomes American -er: centre/center, theatre/theater, metre/meter
- British -ise often corresponds to American -ize: realise/realize, organise/organize (though -ize is also accepted in British English)
- British doubles some final consonants before a suffix where American doesn't: travelled/traveled, cancelled/canceled
- Neither system is 'more correct' — the goal is picking one and using it consistently throughout a single piece of writing
Two systems, one language
British and American English share almost all the same vocabulary and grammar, but differ in a handful of predictable spelling patterns. Recognizing these patterns lets you read both varieties comfortably and choose one consistently in your own writing.
-our/-or and -re/-er
Two of the most common patterns: British -our simplifies to American -or, and British -re becomes American -er.
-ise/-ize and -ogue/-og
British English commonly uses -ise where American uses -ize (though British style guides increasingly accept -ize too). British also keeps a fuller -ogue ending that American often shortens.
Real English
Watch out
Mixing British and American spelling within the same piece of writing (color + centre) looks inconsistent — pick one system and use it throughout.
Neither spelling is an error; they simply belong to different regional standards.
Real life — Editing a document for consistency
"I noticed you've got 'colour' in one paragraph and 'color' in another."
"Oh, good catch — I must have mixed British and American spelling without realizing."
"No big deal, just pick one and I'll help you make it consistent throughout."
"Let's go with American spelling since most of our readers are in the US."
Practice
Exercise 1 · Choose the American spelling
Choose the American spelling of 'colour'.
Exercise 2 · Choose the British spelling
Choose the British spelling of 'center'.
Exercise 3 · Choose the American spelling
Choose the American spelling of 'realise'.
Exercise 4 · Choose the American spelling
Choose the American spelling of 'travelled'.
Exercise 5 · Choose the British spelling
Choose the British spelling of 'catalog'.
Exercise 6 · Choose the correct answer
Which is generally considered good practice when writing a single document?
Exercise 7 · Choose the British spelling
Choose the British spelling of 'defense'.
Exercise 8 · Choose the correct pair
Which pair correctly shows British vs. American?
Exercise 9 · Give the American spelling
Give the American spelling of the British word 'organise'.
Exercise 10 · Give the British spelling
Give the British spelling of the American word 'theater'.
Exercise 11 · Sort the words into groups
0 / 8 sorted
Quick challenge
Five quick questions to check what stuck.
Question 1 / 5
Score: 0/0
Choose the American spelling of 'honour'.
You learned
- British -our often becomes American -or: colour/color.
- British -re often becomes American -er: centre/center.
- British -ise often corresponds to American -ize: realise/realize.
- British sometimes doubles a consonant before a suffix where American doesn't: travelled/traveled.
- Neither system is more correct — consistency within one piece of writing is what matters.
Related grammar lessons
Words Ending in -y and -ie
Learn when a final y changes to i before a suffix (and when it doesn't), plus the special rule for words ending in -ie before -ing — study → studied, but studying; play → played; die → dying.
Words Ending in -e
Learn when to drop a word's silent final -e before adding a suffix, and when to keep it — drop before a vowel suffix like -ing, keep before a consonant suffix like -ly — plus the small set of exceptions that keep the -e to avoid confusion or preserve pronunciation.
Doubling Consonants
Learn the rule for doubling a word's final consonant before adding -ed, -ing, -er, or -est — the 'one vowel, one consonant' pattern for short words, and the stress-based version of the same rule for longer words.
Adding -s, -ed and -ing
An overview of why English spelling shifts when you add -s, -ed, or -ing to a word — the general idea that spelling changes exist to protect pronunciation — with the specific rules (doubling, dropping -e, changing y to i) each getting their own dedicated lesson.