Spelling differences between British and American English

The spelling difference between British and American English is the most evident difference on paper. The primary distinction is that British English retains the spelling of terms borrowed from other languages, primarily French and German. While American English spellings are primarily determined by how a word sounds when spoken.

The spellings of British English words were cemented by Samuel Johnson in what is considered to be one of the most famous dictionaries in the world. It took Johnson, and six helpers, just over eight years to curate the 40,000 words that appeared in ‘A Dictionary of the English Language’, which was published in 1755.

Similarly in America ‘A Compendious Dictionary of the English Language’ was first printed in 1806 and popularised the American English spellings that were being used instead of the British English spellings of words, such as ‘color’ instead of ‘colour.

The author was Noah Webster who followed up the original dictionary in 1828 with his ‘An American Dictionary of the English Language’ which had over 70,000 words.
Samuel Johnson, the author of one of the world’s most famous dictionaries, established the spelling of British English terms. The 40,000 words in ‘A Dictionary of the English Language,’ published in 1755, took Johnson and six assistants just over eight years to compile.

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

British English words ending in ‘our’ usually end in ‘or’ in American English:

These French influenced words have more spelling differences between British and American English. Nearly all of these words originally come from Latin.

British	American
arbour	arbor
ardour	arbor
armour	armor
behaviour	behavior
clangour	clangor
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

British English words that end in -re often end in -er in American English:

The –re spelling originally comes from French.

Verbs in British English that can be spelled with either ‘ize’ or ‘ise’ at the end are always spelled with ‘ize’ at the end in American English:

British	American
apologize or apologise	apologize
organize or organise	organize
recognize or recognise	recognize

Verbs in British English that end in ‘yse’ are always spelled ‘yze’ in American English:

British	American
analyse	analyze
breathalyse	breathalyze
paralyse	paralyze

Words have an -ae- or -oe- in British English but only -e- in US English:

These types of words mostly come from Ancient Greek. Most of these words are scientific, medical, or technical words. Although there are exceptions to the rule.  For example archaeology is spelt in the same way as British English but archeology would be acceptable in America but is incorrect in the UK.

British English	American English
aeon	eon
aesthetic	esthetic
anaemia	anemia
anaesthesia	anesthesia
diarrhoea	diarrhea
gonorrhoea	gonorrhea
gynaecologist	gynecologist
leukaemia	leukemia
manoeuvre	maneuver
oestrogen	estrogen
paediatrician	pediatrician

Some nouns that end with ‘ence’ in British English are spelled ‘ense in American English:

British	American
defence	defense
licence	license
offence	offense
pretence	pretense

Some British english words ends with a ‘silent’ -e. American english omit the -e:

Where both American and British English have this, in words such as name, make, or have, it comes from an Old English inflection. 

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

Some nouns that end with ‘ogue’ in British English end with either ‘og’ or ‘ogue in American English:

British	American
analogue	analog or analogue
catalogue	catalog or catalogue
dialogue	dialog or dialogue

In British spelling ‘L’ is doubled in verbs ending in a vowel plus ‘L’. In American English, the ‘L’ is not doubled:

British	American
fuelled	fueled
fuelling	fueling
travel	travel
travelled	traveled
travelling	traveling
traveller	traveler

Other differences between UK and USA english spellings:

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