Spelling

Exceptions to spelling rules are common on both sides of the Atlantic. Therefore, when in doubt, the UOC recommends using the preferred spellings provided in the Oxford Dictionary for British English and the Merriam-Webster Dictionary for American English.

Please note that, unlike many other authoritative British English sources, the Oxford Dictionary uses the -ize spellings of words like organize and maximize. For more information on this difference, see the relevant section below.

To see how to access the subscription-based Oxford Dictionary of English as a member of the UOC community, see the UOC Language & Style site’s Resources page. Information on many spelling conventions can also be found in the Oxford Learner's Dictionary, which can currently be accessed for free.

Notwithstanding the many exceptions, some of the most common differences between British English and American English spelling conventions are discussed below:

-ae-/-e- and -oe-/-e-

British English has retained the digraphs -ae-and -oe- in certain words of primarily French, Latin and Greek origin that American English spells with a bare e. Examples:

British	American
paediatrician	pediatrician
anaemia	anemia
amoeba	ameba
oestrogen	estrogen

However, some words can be, and often are, spelled with the digraph in American English, too, although the bare e spelling is also accepted. Examples:

aesthetics (or esthetics)

archaeology (or archeology)

Likewise, certain words may be spelled with either the digraph or the bare e in British English. Examples:

encyclopaedia (or encyclopedia)

mediaeval (or medieval)

As a general rule, the UOC prefers to follow Oxford spelling (e.g. aesthetic, archaeology and oestrus but medieval), although the overarching rule is always to be consistent throughout your text. When in doubt, check the Oxford Dictionary.

-ce/-se

British English generally uses the spelling -ce for nouns and -se for verbs. Examples:

a licence but to license

some practice but to practise

American English preserves this distinction with some words (e.g. some advice but to advise) but in other cases always uses -se (e.g. defense or license).

-e before suffixes

Unlike American English, British English retains the final silent e in certain words when adding suffixes. Compare:

British	American
acknowledgement	acknowledgment
ageing	aging
judgement	judgment
likeable	likable
saleable	salable
sizeable	sizable

Nevertheless, for some words, both spellings are accepted in both the UK and the USA. American English tends to be more flexible than British English in this regard. Examples:

acknowledg(e)ment

judg(e)ment

Note, however, that in legal contexts, the spelling judgment is generally preferred in both American and British English.

-ise/-ize and -yse/-yze

While British English often prefers to spell this and related suffixes (-isation, -ising, etc.) with an s, American English uses only the version with z. Compare:

British	American
organise/organize	organize
maximise/maximize	maximize
philosophise/philosophize	philosophize

This notwithstanding, the Oxford Dictionary prefers to spell these words according to their etymological origin, the Greek root -izo, and thus also uses the z spelling.

Similar differences are found with the suffix -yse/-yze. Compare:

British	American
analyse	analyze
catalyse	catalyze
hydrolyse	hydrolyze
paralyse	paralyze

In this case, the Oxford Dictionary uses the s spelling, as these words are formed from a different Greek root, lyo, rather than from -izo. For more information on Oxford spelling conventions, see the Wikipedia entry Oxford Spelling.

Separately, please note that some words are always spelled with an s in all varieties of English. This is generally because the -ise is actually part of a longer component of the word, such as -cise, -prise or -vise, rather than a separate suffix in itself. Nevertheless, a smaller group are always spelled with z. Examples:

Always -ise	Always -ize
advise	capsize
comprise	prize
compromise	seize
excise	size
revise
supervise
televise

-ll-/-l-

British English generally doubles the final l before adding -ed, -ing, -er, -est or -or in words with an unstressed final syllable. American English generally does not. Examples:

British	American
cancellation	cancelation (although cancellation is also accepted)
labelled	labeled
modelling	modeling
traveller	traveler

In contrast, British English often uses a single l in words formed from monosyllabic root words ending in ll and many of their derivatives, whereas American English generally retains the double l. Compare:

British	American
enrol	enroll
enrolment	enrollment
fulfil	fulfill
fulfilment	fulfillment
instalment	installment
wilful	willful

-our/-or

Words ending in an unstressed -our/-or in which the vowel sound is reduced (i.e. the ending is pronounced -er) generally take a u in British English but not in American English. Compare:

British	American
behaviour	behavior
colour	color
favour	favor
neighbour	neighbor

The u is used in American English, too, when the vowel sound is not reduced (i.e. when the ending is pronounced -or). Examples:

contour

paramour

troubadour

-re/-er

Certain words, mainly of French, Latin and Greek origin, that originally ended in a consonant + -re retain that spelling in British English but are spelled with a final -er in American English. This mainly occurs in words in which the -re/-er is unstressed and is particularly common when the preceding consonant is a b or a t. Examples:

British	American
centre	center
fibre	fiber
litre	liter
theatre	theater

Note, however, that British English uses metre for the unit of length, but meter for the measuring instrument.

Likewise, some words retain the original -re spelling in American English, too, particularly when it is preceded by a c or when the original French pronunciation has been retained. Examples:

acre

massacre

mediocre

genre

double entendre

but also macabre, timbre

-t/-ed in past tenses

In British English, the past forms of certain verbs may be spelled with a -t or -ed, whereas in American English they almost exclusively end with -ed. Compare:

British	American
burnt/burned	burned
dreamt/dreamed	dreamed
learnt/learned	learned

That said, both spellings are understood and accepted in both the UK and the USA. In keeping with its leaning towards more internationally understandable English, it is generally UOC policy to use the -ed form. Example:

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Note, too, that British English and American English tend to use different forms for the past participle of the verb to get. Whereas British English generally uses the forms get-got-got, except in certain set phrases (e.g. ill-gotten gains), American English generally uses get-got-gotten, except with the possessive have got (e.g. I've got three pens). Compare:

British: Information they had got from the internet.

American: Information they had gotten from the internet.

-wards/-ward

While both -wards and -ward can be found on both sides of the Atlantic, British English tends to favour -wards, while American English tends to favour -ward. Thus:

British	American
backwards	backward
forwards	forward
towards	toward

This is particularly true when the words being formed function as adverbs. In contrast, when they function as adjectives or as part of a phrasal verb, the suffix -ward generally prevails on both sides of the Atlantic. Examples:

a backward glance

an untoward remark

to look forward to

Other spelling differences

In addition to the above, several common words that do not fall into any of the above categories are also generally spelled differently in British versus American English. These include, among others:

British	American
aluminium	aluminum
cheque (n.)	check (n.)
grey	gray
jewellery	jewelry
mould	mold
per cent	percent
plough	plow
programme (except in computing)	program
sceptical	skeptical
tyre (n.)	tire (n.)

Finally, the words while and among may also be written whilst and amongst. Although the -st spellings are more common in British English than in American English, both variations are accepted. In general, with a view to making its texts as accessible as possible to an international audience, the UOC prefers to use the simplified spellings while and among. As always, however, the most important thing is to use whichever form you choose consistently within your text.