9 Spelling Differences Between British and American English

It is sometimes joked that the United Kingdom and the United States are two countries separated by a common language. Indeed, while the British and the Americans understand each other the vast majority of the time, there are still many important differences between UK and US English, which can lead to confusion or humorous misunderstandings.


On paper, the most obvious difference between British and American English is the spelling (just as when speaking, the most obvious difference is pronunciation).

The spelling differences first arose because at the time of the British colonization of North America, English spelling wasn’t yet fixed. Standardized spelling of English came about in the 18th century, after the American Colonies had already declared independence.

Further spelling differences came when Noah Webster (founder of Webster’s Dictionary) attempted to simplify English spellings in America. Many of his suggestions – like plow – took hold and became standard American spelling. Others – like tung (for “tongue”) – did not.

Below we have listed the main spelling differences that exist between British and American English.

1) -ae- v –e-

Many words that come from Ancient Greek have an –ae– in British English but only –e- in US English. Most of these words are scientific, medical, or technical words.

British American
aeon eon
aesthetic esthetic
anaemia anemia
anaesthesia anesthesia
gynaecologist gynecologist
paediatrician pediatrician

2)  Doubled consonants

Sometimes British spelling requires a doubled consonant, for example in the past participle of certain verbs, where American spelling omits it. In other places, it is US English that has the doubled consonant; in certain verbal infinitives, or to preserve the root word of certain adjectives.

British American
appal appall
carburettor carburetor
counsellor counselor
dishevelled disheveled
distil distill
enrol enroll
fulfil fufill
instalment installment
instil instill
skilful skillful
woollen woollen

3)  -ence v –ense

Many nouns that end in –ence in British English end in –ense in the US. UK English only uses –ense for the corresponding verb; for example, you can license someone to do something, after which they hold a licence to do it.

British American
defence defense
licence(noun) license
offence offense
pretence pretense

4)  Final –e

On both sides of the Atlantic, English is famous for the “silent” –e at the end of many words. Where both American and British English have this, in words such as name, make, or have, it comes from an Old English inflection. But many final –e spellings come from French loanwords,where often the consonant before the final –e is doubled. American English tends to omit these in accordance with Noah Webster’s spelling reforms.

British American
annexe annex
glycerine glycerin
gramme gram
grille(noun) grill
programme program
tonne ton

The words axe (UK) and ax (US) follow this pattern, though the word comes from Germanic (not French) roots. The word judgement (UK) and judgment (US) can also be taken as an example of this if we discard the suffix –ment.

5)  -oe- v –e-

Like –ae- above, British English preserves the –oe- digraph in words derived from the Classical languages, while US English has simplified it to –e-.

British American
diarrhoea diarrhea
gonorrhoea gonorrhea
manoeuvre maneuver

6)  -our v –or

This is one of the more famous spelling differences between British and American English, and comes from French influence. Nearly all of these words originally come from Latin, and had the plain –or ending.

British American
arbour arbor
ardour arbor
armour armor
behaviour behavior
British American
candour candor
clamour clamor
colour color
demeanour demeanor
endeavour endeavor
favour favor
flavour flavor
harbour habor
honour honor
humour humor
labour labor
neighbour neighbor
odour odor
parlour parlor
rancour rancor
rigour rigor
rumour rumor
saviour savior
savour savor
splendour splendor
tumour tumor
valour valor
vigour vigor

7)  -re v –er

Like –our, the –re spelling originally comes from French. In the United States it was replaced with –er to better reflect American pronunciation.

British American
calibre caliber
centre center
fibre fiber
litre liter
lustre luster
meagre meager
metre meter
sabre saber
sceptre scepter
sepulchre sepulcher
sombre somber
theatre theater

-ize v –ise and -yse v –yze


One of the most famous spelling differences isn’t really a difference at all. It’s a common misconception that in the the US you must use spellings like civilize (which is true) but in the UK you must use spellings like civilise (which is not true). In fact, both the –ize and –ise spellings are valid in the UK. Many British people use –ise spellings exclusively, but this is a convention, not a rule. You cannot use –ise spellings in the US.

By contrast, the –yze ending in words like analyze and paralyze is only acceptable in US English. In the UK you must use analyse and paralyse.

9)  Other Simplifications

Many American spellings do owe their existence to Noah Webster’s spelling reforms, which sought to simplify spelling and bring it closer to common American pronunciation.

British American
aeroplane airplane
artefact artifact
British American
cheque(banking) check
chequerboard checkerboard
chequered checkered
cosy cozy
doughnut donut
draught draft
gaol jail
grey gray
jewellery jewelry
kerb(noun) curb
plough plow
sceptical skeptical
sulphur sulfur

Of course, thanks to the impact of globalised media and the internet, the lines are becoming increasingly blurred for many. In fact, you could argue that both varieties of English are being overtaken by textspeak which has no boundaries…


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