The Complete List of
English Spelling Rules

Lesson 20: Differences between
British and U.S. English

In this series of lessons, you will learn useful spelling rules in English.

This final lesson will talk about some common differences between British and U.S. English spelling. Of course both forms are correct, but it is important for you to use one style of English consistently in your writing.


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Several of the rules below talk about suffix spelling differences between British and U.S. English. There are also some rules you should remember about double consonants when adding endings to words.

Finally, there is a list of some common words that are spelled differently. These cannot be explained by a simple rule, so you should learn them separately. 

These are only the most common spelling differences that you will see frequently. You will find more examples as you encounter new words and read different kinds of texts.

1. -ise versus -ize and -yse versus -yze

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In British English, the ending -ise for verbs is more common, though some words also end in -ize. In U.S. English, -ize is much more common, but you will also find some verbs that end in -ise.

This difference applies to words with Greek roots. But instead of looking up each new word's root, you should simply study this list of the most common words with a different spelling in British and U.S. English.

You will also see that some words are spelled -yse in British English, while they end in -yze in U.S. English.

British English	U.S. English
realise	realize
recognise	recognize
finalise	finalize
analyse	analyze
paralyse	paralyze
catalyse	catalyze

Also remember that when you add noun suffixes to these words, they will maintain their s or z, depending on the spelling rules you choose.

So, organise becomes organisation, but organize becomes organization. Realise becomes realisation while realize becomes realization.

2. -our versus -or

Which flavour / flavor of ice cream is your favourite / favorite?

One of the most common differences between British and U.S. English spelling is the our / or variation.

Here are some common words with this spelling difference:

British English	U.S. English
colour	color
behaviour	behavior
labour	labor
neighbour	neighbor
harbour	harbor
rumour	rumor
honour	honor

3. -re versus -er

You should drink between two and three litres / liters of water every day.

Although there are many words that end in -er in British English, you will not find the -re ending in U.S. English. Remember that this difference only applies to root words. So, the comparative -er ending is the same in both styles.

Here are the most common examples of this spelling difference:

British English	U.S. English
calibre	caliber
centre	center
theatre	theater
sabre	saber
metre	meter
sombre	somber

4. Doubling the final L in British English

James is travelling / traveling to Asia for the first time.

When we add endings to words that end in l (the verb endings -ed, -ing, -er, and -est, or the noun suffixes -er and -or), the word's final l is usually doubled in British English.

In U.S. English, the final consonant is usually only doubled when the stress is on the final syllable of the word and the words ends in a single consonant and a single vowel. Check the articles on adding -ed and adding -ing for more details.

Here are some of the most common words with this spelling difference:

British English	U.S. English
cancelling	canceling
crueller	crueler
signalled	signaled
labelled	labeled
modelling	modeling
counsellor	counselor
traveller	traveler

5. Miscellaneous spelling differences

This is an elevent-storey / story building.

There are also some common words that are spelled differently in the two styles, but do not respond to a specific rule. Here are some of the most important ones you should study.

British English	U.S. English
aeroplane	airplane
aluminium	aluminum
cheque	check
cosy	cozy
furore	furor
kerb	curb
mould	mold
moustache	mustache
pyjamas	pajamas
sceptical	skeptical
speciality	specialty
sulphur	sulfur
tyre	tire

Review

So, let's review what we have learned about the differences in spelling in British and U.S. English:

1. The suffixes -ise and -yse are more common in British English, while -ize and -yze are more common in U.S. English.
   
   
2. The ending -our is more common in British English, while -or is more common in U.S. English.
   
   
3. The ending -re is more common in British English, while -re is more common in U.S. English.
   
   
4. The final l is doubled in words in British English when certain word endings are added (-ing, -ed, -er, -est, and -or), while the final l is only doubled when the stress is on the final syllable and the root word ends in a single consonant and a single vowel in U.S. English.
   
   
5. There are also some common words that have a different spelling in British and U.S. English but do not follow specific rules. 

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