Everything you need to know about American and British spelling differences


We cover essential rules, exceptions and alleged differences that aren’t actually differences at all!

two naked sole of foot with happy faces drawn on toes

Caption that sleepwear!

“Those are grey checkered pyjamas.” What’s wrong with this photo caption?

English teachers in the UK and the US would both tell you this sentence contains spelling errors. But they would identify different errors. Can you spot them?

A British teacher would tell their pupils to write “grey chequered pyjamas”. An American would spell it “gray checkered pajamas”. Both would find the other spelling variant in flagrant violation of accepted spelling rules.

When writing in English, it’s key to choose one version of English and use it consistently, whether that be British, American, Canadian or Australian. If you mix and match your spelling rules, your text will end up confusing your readers.

You probably already know some of the spelling differences between British and American English. Something to do with the letters s and z, right?

It’s actually more complicated than a few simple rules, but there are several patterns to help you remember spelling differences. The most important general rule to remember: British spellings often (but not always) have more letters than their American English counterparts. We’ve got a comprehensive guide for you below. We explain which rules you need to follow to be understood by your target audience and which spelling rules are optional.


First, a quick word on why the two languages are so different. Attempts to standardise English spelling date as far back as the early fifteenth century. At first, British and American English both relied strongly on Samuel Johnson’s comprehensive dictionary from the mid-18th century.

Things started to change in the early 19th century, however. A lot of the spelling differences that exist today between British and American English originated with one man and his mission. Noah Webster (1758–1843) believed that the United States needed more clearly defined cultural independence from Great Britain. Language and spelling reform, in particular, were his means to this end. He wrote the first American English grammar textbook and compiled the first American dictionary. Well, good job, Noah. You succeeded. British and American English are truly different languages now. To this day, the Merriam-Webster dictionary, which traces its lineage back to Webster’s original American dictionary, is the first stop for anyone looking up words in American English. Meanwhile, on the other side of the Atlantic, the Oxford English Dictionary, which was first published in its entirety in 1928, remains to this day the most extensive dictionary of the English language anywhere. Other widely accepted reference works for British English include the Cambridge English Dictionary. (And if your library or company does not have a subscription to the Oxford English Dictionary, you can always use the standard Oxford Dictionary, which is slightly less comprehensive.)


More letters in British than in American English

We have Noah Webster to thank for the fact that many spelling differences between British and American English come down to American English using fewer letters. He valued spelling words as they were pronounced and reducing unpronounced letters. (Not all his suggested reforms caught on in American English, however. His preferred spelling of “tung” for “tongue” was never widely used.)

The –our vs –or difference

This is one you probably already know. Here are a few examples:

British

American

armour

armor

behaviour

behavior

favour

favor

favourite

favorite

harbour

harbor

mould

mold

moustache

mustache, (moustache also acceptable, but not as common)

smoulder

smolder

American English drops the e

There are three cases where American English will drop an e and British English will keep it.

First, when a noun, such as “judgement”, is formed by adding –ment to a verb ending in –dge (in this case: to judge), American English drops the e. Resulting in “judgement” in British English and “judgment” in American English. One exception: British legal texts tend to exercise “judgment” over “judgement”.

Second, when adjectives, such as “sizeable”, are formed by adding –able to a one-syllable word “size”, American English will drop the e to form “sizable”. British English keeps the e: “sizeable”.

Note, however, that both versions of English recognise the other form as an alternative, but not preferred, spelling. Searching through the entire “New York Times” archive online yields ca. 23,000 hits for “sizable” and only 1,800+ hits for “sizeable”. Archives for the “The Guardian”, in contrast, reveal ca. 5,000 hits for “sizeable” and 1,360 results for “sizable”.

Third, the gerund form of “to age”. The correct form in the UK is “ageing", and the preferred US spelling is “aging” (although the British spelling is an acceptable alternative).

British

American

abridgement

abridgment

acknowledgement

acknowledgment

judgement

judgment

blameable

blamable

hireable

hirable

likeable

likable

moveable

movable

sizeable

sizable

ageing

aging (ageing also acceptable, but not as common)

It’s all Greek to us: -ae/-oe vs –e 

Words derived from the Greek maintain their double vowels (ae or oe) in British English. American English tosses those extra a’s and o’s out the window. This is especially common in medical terminology. Below is a small selection of examples:

British

American

aeon

eon

coeliac

celiac

encyclopaedia

encyclopedia

foetus

fetus

homoeopathy

homeopathy

leukaemia

leukemia

manoeuvre

maneuver

oestrogen

estrogen

The great catalogue debate: –ogue vs –og

If spelling reforms are going to succeed, they need the support of the people. There have been many unsuccessful attempts at spelling reform in both American and British English, whose suggestions now look preposterous to many native speakers. (“Vejetabl” instead of “vegetable”? “Fadher” for “father”?) And as passionate as Noah Webster was about making American English its own language with its own spellings, there were many points where the American people simply disagreed.

Remember his failed reform of “tongue” to “tung”? His penchant for deleting the –ue in nouns met with resistance elsewhere, as well. Many nouns ending in –ogue have two spelling variants in American English that battle on to this day. Language and spelling are not always as neat and simple as Noah Webster and other spelling reformers wanted them to be. Language is a living thing, which sometimes seems to have a will of its own. As one writer puts it, “Language has the dispositions [sic] of a teenager; it always follows the crowd”.

Alongside “dialog”/ “dialogue”, the “catalogue”/“catalog” debate is the best example of this, as this google Ngram shows. The spelling “catalog” is currently ahead of “catalogue”, but this has only happened in the past 40 years. The proper spelling of this word in American English can cause fairly intense debates, especially among librarians! The “card catalogue”/“card catalog” may be redundant in the digital era, but American librarians now have to decide if a library has an “online catalog” or an “online catalogue”.


Similarly, both spellings – “dialog” and “dialogue” – are acceptable in American English when discussing a conversation between two people, although there is a stronger preference for “dialogue”. “Dialog”, however, is always the correct spelling in American English for exchange between a person and a computer, such as in the phrase “dialog box”. And this spelling of “dialog” as a technical term has made its way across the Atlantic, where it is gaining acceptance. (Although not enough acceptance to make it into the Oxford dictionary as anything other than an American variant.)

“Analogue” follows a similar pattern in American English. When it functions as an adjective meaning non-digital, it should always be spelled “analog”. When it is a noun meaning something analogous to something else, then it is written “analogue”, although “analog” is an acceptable variant.

As for most of the other –ogue terms such as epilogue, monologue and prologue, the –og spelling never caught on. A single newspaper in the United States applied these spellings up until 1975, when it finally gave up.

Don’t believe other language guides that suggest Americans spell all the words below without the –ue. As this Google Ngram shows, this simply isn’t the case! The American people disagreed with Noah Webster on this matter.

 

British

American

catalogue

catalog / catalogue

dialogue

dialog / dialogue

monologue

monologue

analogue

analogue / analog

epilogue

epilogue

prologue

prologue

To double l or not to double l?

L’s are another difference between British and American English. In general, British English uses double l’s when forming words based on other words ending in a vowel plus –l. For example, the verb “duel” when used in its –ing form (called its gerund form), as in the phrase “duelling banjos”, takes an extra l in British English. But in American English, a single l is used: “dueling banjos”. Below are a few examples of this:

British

American

counsellor

counselor

duelling

dueling

funnelled

funneled

reveller

reveler

spiralling

spiraling

squirrelled

squirreled

travelling

traveling

unrivalled

unrivaled

woollen

woolen

The exception to the rule: flipping the double l

Just when you were getting comfortable, we’ve got an exception to the general rule of “British English often uses more letters, especially where l’s are concerned”. There are some words for which American English takes a double l and British English doesn’t. For example, British English: distil. American English: distill. But they meet in the middle and agree on the gerund and the adjective form: “distilling” and “distilled”.

This rule is not always easy to apply across the board, however, as there are some cases where British English takes the double l just like American English. For example, in British English, you might install (double l) the world’s largest television on your living room wall. But you watch the next instalment (single l) of the “Star Wars” on that 200-inch telly. It’s best to always look these up! Some examples:

British

American

appal

appall

enrol

enroll

enthral

enthrall

fulfilment

fulfillment

install, instal (also acceptable)

install

instalment

installment

instil

instill

skilful

skillful

wilful

willful

Miscellaneous words with more letters in British English 

Finally, we have a mishmash of words that don’t fit into the other categories. Many owe their shortened American spelling to Webster’s spelling reform. For example, some words are spelled with a ph in British English and an f in American English. Also, you’ll notice that many of the differences below come from British English retaining an original spelling from a foreign language, such as “omelette”, which comes from the French.

British

American

aeroplane

airplane

aluminium

aluminum (note, this word is also pronounced differently)

axe

ax (axe also acceptable)

baulk

balk

carburettor

carburetor

cheque

check (bank)

chequered

checkered

chequers (game)

checkers

doughnut

donut, doughnut

draught

draft

draughtsman

draftsman

flautist

flutist (note, this word is also pronounced differently)

furore

furor

glycerine

glycerin

gram, gramme (less common)

gram

jewellery

jewelry

liquorice

licorice

omelette

omelet

pernickety

persnickety (note, this word is also pronounced differently)

phoney

phony

pitta bread

pita bread

plough

plow

programme

program

snowplough

snowplow

speciality

specialty (note, this word is also pronounced differently)

storey (level of a house)

story

sulphur

sulfur

sulphate

sulfate

tartare sauce

tartar sauce

tonne

ton

 

Give me an S! No, give me a Z! The s/c/z confusion

S creates a lot of problems for both Americans and the British.

–ence or –ense? What makes sense?

First, we have the case of British English using the letter c in certain nouns, such as “defence”, and American English using an s, “defense”. But then, in a sincerely sneaky rule, these differences apply only to nouns in British English. To use a proper British example, James Bond is licensed (s!) to kill. He also holds a driving licence (c!). But in the US, they’d say he is licensed to kill (s!), and he holds a driver’s license (s!). Or does he?

Watch out for the word “practice”, though! It behaves against type in American English, where it always takes a c.

British

American

defence

defense

licence (noun)

license (verb)

license (noun and verb)

offence

offense

practice (noun)

practise (verb)

practice (noun and verb)

pretence

pretense

The –ise vs –ize debate

Many people will tell you that British English uses –ise for words such as “realise”, “publicise” or “summarise” whereas American English takes a –ize ending: “realize”, “publicize”, “fraternize”. People who tell you this are right. Kind of. British media often uses the –ise spelling, while American media does not. However, remember the Oxford English Dictionary we mentioned above? The most authoritative dictionary for British English? The –ize ending is actually the older British form. This is why Oxford lists –ize endings as the primary spelling and –ise as an alternative spelling. But the British people don’t always agree. And, as we said above, language is like a teenager. It follows the crowd.

Just as Americans can’t agree whether “catalogue” or “catalog” is the correct spelling, the UK is similarly divided about those –ise/–ize endings. Take a look at the occurrence of “realize” vs “realise” in British books. Currently, the –ize ending is performing surprisingly well. But, if you want to play it safe in British English, we would always recommend the –ise spelling, as that is still the most common in media, government and education.


What does this mean? If you’re writing in British English, you can chose if you want to “utilize” or “utilise” the –ize ending in British English. Preferencing –ize over –ise spelling in British English is known as “Oxford English” after the dictionary.

I know what you’re thinking. “Great! I will always use the z in British English instead of the s and say I’m using Oxford English!” Not so fast. The Oxford English rule only applies to –ise endings and does not also apply to –yse words, such as “analyse” and “paralyse”. Also British English uses an s in “cosy”, whereas American English takes a z.

British

American

analyse

analyze

catalyse

catalyze

cosy

cozy

paralyse

paralyze

finalise, finalize

finalize

generalisation, generalization

generalization

immunisation, immunization

immunization

itemise, itemize

itemize

memorise, memorize

memorize

 

The –re vs –er difference

This difference is fairly straightforward. From a “sabretooth tiger” to breakfast-cereal “fibre”, British English often ends words in –re, whereas American English takes –er.

Interestingly, “theatre” is one spelling that has caught on in American English – but only in reference to the stage, not the movie theatre. Many theatres and theatre organisations chose the –re ending for their proper name. This list includes most Broadway theatres, such as the New Amsterdam Theatre and the Helen Hayes Theatre; Los Angeles’s Center Theatre Group (note only “theatre” is spelled according to British convention, not “center”!); and the journal American Theatre. It must be because so much good theatre comes from the UK.

British

American

calibre

caliber

centre

center

fibre

fiber

lacklustre

lackluster

litre

liter

meagre

meager

metre

meter

theatre

theater, theatre

 

The rule-breakers: rebellious spelling differences that follow no discernible pattern

You’ve made it through the list of spelling differences between British and American English! You’ve learned most of the key rules. All that’s left are the miscellaneous spelling differences for commonly used words, which we’ve put together into one last table for you.

British

American

artefact

artifact

behove

behoove

carat

karat

dependant (noun meaning a person dependent on someone else)

dependent

enquire

inquire

enquiry

inquiry

grandad

granddad

grey

gray

kerb (noun denoting the edge to the pavement)

curb

mollusc

mollusk

pedlar

peddler

pyjamas

pajamas

on to, onto (two words more common)

onto

sceptic

skeptic

sceptical

skeptical

tyre

tire

vice

vise (metal tool with moveable jaws)

whisky (Ireland uses whiskey)

whiskey

worshipper

worshiper, worshipper (less common)

 

Spelling differences that aren’t

Even though it might not seem this way, British and American English speakers actually agree on spelling more often than we disagree. There are a few mythical spelling differences floating around on the internet like outdated rumours. You might read about the following alleged spelling differences. Spoiler alert: they aren’t actually spelling differences in common usage today!

For example, some spelling guides will tell you that British English uses the spellings “connexion” and “reflexion” from the original Latin. They may have once used these spellings, but it went out of style in the 19th century. Certain company names do use them, but as general spellings they are considered archaic.



The American English example that you’ll often hear is that Americans spell the preposition “through” as “thru” and “though” as “tho”. This is only true in textspeak and informal writing.

The same holds true for “nite” and “lite”. Don’t believe what you hear, the proper US spelling is also “night” and “light”. The dieting and food industries are perhaps the only sectors where “lite” is an acceptable spelling.

A final pro tip: if you’re writing in Microsoft Word, you can adjust your spellcheck settings for British or American English (or Canadian, Australian, South African or New Zealand English). But if you’re writing in British English and you prefer –ise endings to –ize endings, make sure to do a manual search for the “iz” letter combination. Like the Oxford English dictionary, Microsoft Word recognises both –ise and –ize as correct in British English.

Need help improving your English? Contact our key account managers to book in-company English classes with us in the Hamburg or Frankfurt area. You can also book one of our language seminars anywhere in Europe.

Need someone to check your English-language text for consistency in British or American English? Get in touch with our project managers for a free proofreading offer.

By Mara T.

 

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