British vs American Spelling: 50 Differences Every Child Needs to Know
The complete reference for parents and teachers — with Canadian and Australian conventions included for every word.
Published April 2026 · SpellCrush Team
English is spoken across dozens of countries, but it isn't spelled the same everywhere. British English, American English, Canadian English, and Australian English each follow their own conventions — and the differences affect exactly the kinds of everyday words that children practise at school.
For parents using spelling apps, this matters. An American app will teach 'color' to a child whose teacher expects 'colour.' A British app will teach 'organise' to a Canadian child whose school uses 'organize.' The result is confusion, incorrect practice, and wasted effort.
This guide lists the 50 most common spelling differences that children are likely to encounter, organised by the rule that governs each group. For every word, we show the British, American, Canadian, and Australian convention — so you can see exactly which variant your child needs.
1. The -our / -or Rule (10 Words)
British, Canadian, and Australian English use -our (colour, favourite, honour). American English drops the U and uses -or (color, favorite, honor). This is the single most common spelling difference children encounter.
| British 🇬🇧 | American 🇺🇸 | Canadian 🇨🇦 | Australian 🇦🇺 |
|---|---|---|---|
| colour | color | colour | colour |
| favourite | favorite | favourite | favourite |
| honour | honor | honour | honour |
| behaviour | behavior | behaviour | behaviour |
| neighbour | neighbor | neighbour | neighbour |
| labour | labor | labour | labour |
| flavour | flavor | flavour | flavour |
| humour | humor | humour | humour |
| harbour | harbor | harbour | harbour |
| savour | savor | savour | savour |
Note: Canada, Australia, and the UK all agree on -our. Only American English uses -or.
2. The -re / -er Rule (8 Words)
British, Canadian, and Australian English use -re (centre, metre, theatre). American English reverses the letters to -er (center, meter, theater). Again, all three non-American variants agree.
| British 🇬🇧 | American 🇺🇸 | Canadian 🇨🇦 | Australian 🇦🇺 |
|---|---|---|---|
| centre | center | centre | centre |
| metre | meter | metre | metre |
| theatre | theater | theatre | theatre |
| fibre | fiber | fibre | fibre |
| litre | liter | litre | litre |
| sombre | somber | sombre | sombre |
| lustre | luster | lustre | lustre |
| spectre | specter | spectre | spectre |
3. The -ise / -ize Rule (8 Words)
This is where the variants diverge from each other. British and Australian English prefer -ise (organise, recognise). American and Canadian English prefer -ize (organize, recognize). This is one of the key rules that makes Canadian English a genuine hybrid — it follows the American convention here despite following British conventions for -our and -re.
| British 🇬🇧 | American 🇺🇸 | Canadian 🇨🇦 | Australian 🇦🇺 |
|---|---|---|---|
| organise | organize | organize | organise |
| recognise | recognize | recognize | recognise |
| specialise | specialize | specialize | specialise |
| apologise | apologize | apologize | apologise |
| realise | realize | realize | realise |
| criticise | criticize | criticize | criticise |
| emphasise | emphasize | emphasize | emphasise |
| minimise | minimize | minimize | minimise |
Important for Canadian parents: This is the rule that trips up Canadian children most. Canadian schools teach 'organize' with a Z — not 'organise' with an S. A British spelling app will get this wrong for Canadian children.
4. The Doubled L Rule (6 Words)
When adding suffixes like -ing or -er to words ending in L, British, Canadian, and Australian English double the L (travelling, cancelled). American English keeps a single L (traveling, canceled).
| British 🇬🇧 | American 🇺🇸 | Canadian 🇨🇦 | Australian 🇦🇺 |
|---|---|---|---|
| travelling | traveling | travelling | travelling |
| cancelled | canceled | cancelled | cancelled |
| jewellery | jewelry | jewellery | jewellery |
| modelling | modeling | modelling | modelling |
| counsellor | counselor | counsellor | counsellor |
| marvellous | marvelous | marvellous | marvellous |
5. Other Common Differences (18 Words)
These words don't follow a single clean rule — each has its own history. Pay particular attention to the Canadian column: Canada follows the British spelling for some of these words (cheque, grey) but the American spelling for others (tire, program).
| British 🇬🇧 | American 🇺🇸 | Canadian 🇨🇦 | Australian 🇦🇺 |
|---|---|---|---|
| programme | program | program | programme |
| catalogue | catalog | catalog | catalogue |
| cheque | check | cheque | cheque |
| grey | gray | grey | grey |
| tyre | tire | tire | tyre |
| defence | defense | defense | defence |
| licence (n.) | license | licence (n.) | licence (n.) |
| plough | plow | plow | plough |
| draught | draft | draft | draught |
| aluminium | aluminum | aluminium | aluminium |
| kerb | curb | curb | kerb |
| manoeuvre | maneuver | manoeuvre | manoeuvre |
| pyjamas | pajamas | pyjamas | pyjamas |
| aeroplane | airplane | airplane | aeroplane |
| doughnut | donut | doughnut | doughnut |
| sceptical | skeptical | skeptical | sceptical |
| analogue | analog | analog | analogue |
| ageing | aging | aging | ageing |
Quick Reference: Which Variant Follows Which Rule?
| Rule | 🇬🇧 British | 🇺🇸 American | 🇨🇦 Canadian | 🇦🇺 Australian |
|---|---|---|---|---|
| -our (colour) | -our | -or | -our | -our |
| -re (centre) | -re | -er | -re | -re |
| -ise (organise) | -ise | -ize | -ize | -ise |
| Doubled L (travelling) | LL | L | LL | LL |
| -ence (defence) | -ence | -ense | -ense | -ence |
The pattern is clear: Canadian English follows British conventions for most spelling rules (-our, -re, doubled L) but follows American conventions for -ize words and some individual words (defense, program, tire). Australian English almost always follows British conventions. And British and American English are consistent opposites across every rule.
For children, the practical impact is straightforward: a spelling app needs to know which variant your child uses, or it will teach wrong spellings for a significant number of common words. This is especially true for Canadian children, whose hybrid conventions mean that neither a purely British nor a purely American word list is correct.
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