UK vs US spelling
British and American English share almost all of their spelling rules. The differences come in a handful of patterns, so learning the pattern covers dozens of words at once. Australian and Indian English spell the British way.
Neither spelling is wrong in itself. What matters is which one your child's school teaches, so check that before correcting.
-our and -or
British English keeps the u in words like colour; American English drops it.
| UK | US |
|---|---|
| colour | color |
| favourite | favorite |
| neighbour | neighbor |
| behaviour | behavior |
| honour | honor |
| harbour | harbor |
The u is dropped in British English too before some endings: humour but humorous, glamour but glamorous, vigour but vigorous.
-re and -er
Many words end -re in British English and -er in American English.
| UK | US |
|---|---|
| centre | center |
| theatre | theater |
| metre | meter |
| litre | liter |
| fibre | fiber |
A meter that measures something (a gas meter) is spelled -er in both.
-ise and -ize, -yse and -yze
UK schools usually teach -ise; American English uses -ize. Words ending -yse are only -yse in British English.
| UK | US |
|---|---|
| realise | realize |
| organise | organize |
| apologise | apologize |
| recognise | recognize |
| analyse | analyze |
| paralyse | paralyze |
Some British publishers use -ize (it is called Oxford spelling), so you will see both in books. Words like surprise, advertise and exercise are -ise everywhere.
Doubling l
British English doubles a final l before an ending even when the stress is not on the last syllable; American English usually doesn't.
| UK | US |
|---|---|
| travelled | traveled |
| cancelled | canceled |
| jewellery | jewelry |
| modelling | modeling |
It goes the other way in a few words, where British English has one l: skilful (skillful), fulfil (fulfill), enrol (enroll), instalment (installment).
-ence and -ense
Some nouns end -ence in British English and -ense in American English.
| UK | US |
|---|---|
| defence | defense |
| offence | offense |
| licence | license |
British English uses licence for the noun and license for the verb, the same pattern as practice and practise.
Other everyday differences
These have to be learned one by one.
| UK | US |
|---|---|
| grey | gray |
| mum | mom |
| plough | plow |
| doughnut | donut |
| pyjamas | pajamas |
| aluminium | aluminum |
| tyre | tire |
| sceptical | skeptical |
| catalogue | catalog |
Grey is common in American English too. Tire is also an ordinary British word meaning to grow weary, so it is only 'wrong' when it means the rubber on a wheel.
British noun and verb pairs
British English spells the noun and the verb differently in a few words. American English uses one spelling for both.
| Noun | Verb | Example |
|---|---|---|
| practice | practise | football practice / I need to practise |
| licence | license | a driving licence / licensed to sell |
Correct in British English, even though they look American
- rigorous - from rigour, but the u goes before -ous
- vigorous - from vigour, the same way
- glamorous - from glamour, the same way
- humorous - from humour, the same way
- program - a computer program is spelled program in British English too; a TV programme is not
- check - to check something is British English; only the bank cheque differs