American flag atop a stack of books, an apple to the right, view from above, American spelling versus british

With Independence Day coming up, it’s an apt time to learn about and appreciate the ways American and British culture contrast—one major variation is in the many US vs. UK spelling differences.

While Americans and Brits communicate in the same language, there are so many differences in each respective dialect, including many spelling differences for the same words. Let’s learn about what makes American and British English so different and some favorite—or, favourite— spelling differences between the two!

Language Change Across the Pond: US vs UK Dialect Differences

Dialects are variations of a language that are mutually comprehensible, meaning that two people who speak different dialects of the same language can understand one another. Dialects can differ from one another in many ways: pronunciation (accents), word meanings, and spelling can all differ across dialects.

English Dialects & Accents

Dialects are regional variations of a language. The three major dialects of English are British, American, and Australasian English. Those are each considered the standard “norm” for their particular region, although there are minor dialects across each of them. 

Consider how American English differs across the United States: there’s the “country accent”, spoken across southern states, the “boston accent”, the “midwest accent”, African-American Vernacular English, and so on. The same goes for Great Britain—for such a small country, there is a vast diversity in British accents. There’s Received Pronunciation, also known as “Posh” or “the Queen’s English”, Scottish, “Scouse” (spoken around Liverpool)… some say there are over forty distinct variations.

The Evolution of the English Language

No language remains unchanged over time. English (and every other language spoken today) is the result of hundreds of years of language change. There have been three main eras of the English language: Old, Middle, and Modern. 

Like every language does, Old English formed from a combination of languages—Roman rule of the island made Latin the standard language in Britain until various Germanic languages became involved during the Anglo-Saxon invasion in the 5th century. Throughout the time Old English was spoken, more Latin was loaned to the language as Christianity was introduced to Britain. 

Middle English was shepherded in with the Norman conquest of England in 1066, which collided Old English with Old French and Norse. The immense change from this event made English more distinct from Latin, enriching the language so much that it birthed English literature (Geoffrey Chaucer’s The Canterbury Tales is the most famous example) and eventually replaced Latin as the language governmental proceedings were held in. 

English changed drastically during the 1400s. One major occurrence was the Great Vowel Shift, which changed the pronunciation of many vowels to the way we pronounce them today. (For example, “bite” was pronounced “beet” and “out” was pronounced “uut” before this shift.) English also became more standardized with the use of the printing press, and it borrowed more words from Greek and Latin as a result of greater literacy and globalization. 

By the time Shakespeare began writing, the language was clearly Early Modern English—understandable to us today, though retaining many artifacts of Middle English. Around the time of American colonization, the language became the Modern English we know today.

The American and British English Split

Linguistic change always happens over time, whether a language collides with another or is isolated. This means that the difference between the American and British dialects began to develop as soon as Britain colonized the Americas in the 1600s. By the 1700s, people began commentating on new American manners of speech, and Benjamin Franklin even discussed dialect differences across the different colonies in his 1739 Poor Richard’s Almanack. 

An ocean of separation quickly led to the development of new vocabulary for Americans—finding themselves in a newly discovered land, colonists simply needed to develop more words to describe the plants, animals, and society around them. Cultural exchange with indigenous Americans also contributed to the language’s vocabulary development.

Another major difference across British and American English is pronunciation: the well-known distinction of American and British accents. One of the most impactful differences between the two is that most British accents are “non-rhotic”, meaning they do not pronounce the /r/ sound when it follows a vowel. (For example. Americans pronounce each letter in the word “farmer”, while someone with a British accent would pronounce it “fahmah”, dropping both Rs because they each follow a vowel. ) 

British English became non-rhotic after the American colonies were established, so American English continued to be rhotic—except for major port cities like Boston and New York, which dropped that /r/ sound through frequent trade with Brits. (Think about the Boston accent: they famously say “cah pahk” instead of “car park”.)

Finally, one of the most distinct differences between American and British English is in their spelling. 

US vs UK Spelling—Common Differences

When Britain began to colonize the Americas in the 1600s, there had not yet been a dictionary published that standardized English spelling. In 1755, British writer Samuel Johnson published A Dictionary of the English Language, considered the first great English dictionary. Then, in 1828, Noah Webster published An American Dictionary of the English Language, which established many spelling differences that made American English spelling unique. Historians hypothesize that Webster changed many spellings in order to emphasize Americans’ cultural independence from Great Britain. 

Many UK vs US spelling differences are patterns you can see in words with similar structures, especially suffixes. While many of them have exceptions, these are seven of the most common spelling differences that will catch Americans’ eyes when reading the writing of Brits.

1. “-or” vs “-our”

Most words that end in “-or” in American English are actually spelled with -our in British English. 

Examples of the -or/-our Difference:

  • Flavor / Flavour
  • Behavior / Behaviour
  • Favorite / Favourite
  • Honor / Honour
  • Color / Colour
  • Neighbor / Neighbour

These words were adopted into English from early Old French in the transition between Old to Middle English, matching the French spelling of -our. Then, when more Latin was introduced to Early Modern English after the renaissance, some of those words adopted the -or spelling. After some back-and-forth, Johnson’s 1755 dictionary standardized -our as the spelling, while Webster’s 1828 dictionary is credited for the American adoption of the -or spelling.

While this pattern is nearly ubiquitous across each dialect, there are some exceptions. Most of them are words ending in -our in American English, too: devour, contour, paramour, velour, glamour, hour, tour, and flour. Exceptions that use the -or form are fewer: senior, rigor, and junior.

2.”-er” vs “re”

Many words were adopted into English from Latin, Greek, or French that end in -re, pronounced -er. These words are usually always spelled –er in American English. (This pattern is most common for words ending in -bre or -tre in British English.)

Examples of the -er/-re Difference:

  • Caliber / Calibre
  • Theater / Theatre
  • Specter / Spectre
  • Luster / Lustre
  • Meter / Metre*
  • Somber / Sombre

This difference in British vs. American spelling was also established with Johnson’s 1755 dictionary and Webster’s 1828 dictionary; before this, both variations were common across Britain and America.

There are many exceptions that use -er in both dialects. These include words like disaster, enter, monster, filter, chamber, mother, river, and months like December and October. Exceptions that end in -re in both American and British English include massacre, mediocre, ogre, and acre.

*Meter is a peculiar case. It is spelled with an -er in both languages when referring to the measuring instrument, but with -re when referring to the unit of length in British English.

Words using -meter as a suffix (such as thermometer or pentameter) are spelled with -er across both dialects.

3. “-ize” vs “-ise”

This next difference in American and British spelling has a different origin than the ones above. The -ize word ending has been in use in English since the 1400s, as it entered the language directly from Greek & Latin. Today, it’s the standard in American English, while the same words often end in -ise in British English. 

Examples of the -ize/-ise Difference:

  • Realize / Realise
  • Organize / Organise
  • Recognize / Recognise
  • Apologize / Apologise
  • Jeopardize / Jeopardise
  • Maximize / Maximise

Officially—as per the Oxford English Dictionary—the correct form (across both dialects) is -ize, but -ise is an acceptable alternative. Some verbs ending in -ize take that form across both American and British English, such as seize, capsize, and prize. Others take the -ise form: advertise, advise, revise, surprise, wise, and improvise are some examples.

This pattern also applies to words with a y instead of an i—such as analyze/analyse and paralyze/paralyse.

4. “-ce” vs. “-se”

Some words ending in -ce are also spelled -se, depending on the intended definition or the dialect in which they’re spoken. This spelling difference is not as consistent as others, nor is one ending favored by one dialect across the board. 

Examples of the -ce/-se Difference:

  • Practice (US) / Practise (UK)
  • License (US) / Licence (UK)
  • Defense (US) / Defence (UK)
  • Pretense (US) / Pretence (UK)
  • Advice (Noun) / Advise (Verb) (Both US & UK)
  • Device (Noun) / Devise (Verb) (Both US & UK)

5. “ae”+”oe” vs. “e”

So far, these differences in US vs UK spelling have been about suffixes. There are also variations in spelling mid-word. Many words with Latin and Greek origins are written with ae/æ or oe/œ in British English, where in American English they are just written with an e.

Examples of the ae, oe/e Difference:

  • Anesthesia / Anaesthesia
  • Orthopedic / Orthopaedic
  • Fetus / Foetus
  • Encyclopedia / Encyclopaedia
  • DIarrhea / DIarrhoea
  • Hemoglobin / Haemoglobin

As you can see, many of these words are medical terminology. One more difference is airplane/aeroplane, where the American version replaces the vowel dipthong (meaning two connected vowel sounds) with an i. Americans tend to spell aesthetics and archaeology with the ae, while Brits tend to spell words like chamaeleon and mediaeval both ways.

6. “-og” vs. “-ogue” & “-m” vs. “-mme”

Derived from the Greek ending -logos (meaning “one who speaks”), words ending in -ogue in British English are sometimes spelled with just -og in American English, eliminating the vowels at the end. 

Examples of the -og/-ogue Difference:

  • Analog / Analogue
  • Catalog / Catalogue
  • Demagog / Demagogue

Although, some American words keep the longer spelling—such as for synagogue, dialogue, monologue, and pedagogue.

Similarly, a few British versions of words include the ending -mme, where American versions just end in -m. The most notable instance is programme, the British spelling for a television program. More words were spelled like this in the past, but the difference has simplified over the years—some linguists attribute this to American influence on Britain. (How the tables have turned!)

7. Consonant Doubling

In some words, one dialect prefers to double a consonant when the other doesn’t.

When adding a suffix that begins with a vowel, the final consonant of a word is sometimes doubled. This occurs in both dialects, but mostly in British English.

In words with -ed, -ing, -er, -est, and –or added-on, British English doubles the preceding consonant (usually the letter l). Examples include (with American English listed first):

  • Canceled / Cancelled
  • Counselor / Counsellor
  • Quarreled / Quarrelled
  • Traveling / Travelling
  • Cruelest / Cruellest
  • Labeler / Labeller

An exception is words with the root parallel, which keep a single l at the end to avoid the cluster of llell (unparalleled).

Words ending in -ize/-ise, -int, -ism, -ish, and -ist do not double the preceding consonant. So, in both American and British English, they’re spelled devilish, normalise, novelist, etc. (Exceptions for British English are medallist, panellist, and tranquillise.)

Finally, in American English, words ending in a double-l retain the two consonants when adding a suffix. Brits, on the other hand, tend to remove one of the pair—even without the addition of a suffix. Examples include (with American English listed first):

  • Willful / Wilful
  • Enrollment / Enrolment
  • Fulfillment / Fulfilment
  • Skillful / Skilful
  • Distill / Distil

English Language Arts Help with Piqosity

We hope this dive into US vs. UK spelling was both informative and interesting! The way language develops over time is a puzzling process, influenced by social factors, cultural exchange, and general patterns of simplification over time. Having some context on how words form can help you remember vocabulary and word spelling, so try learning about etymology if you struggle learning new vocabulary.

If you want to improve your reading and writing skills more this summer, Piqosity can help! We offer full online ELA courses, each including dozens of concept lessons, personalized practice software, and over 100 reading comprehension passages. We also offer full Math courses for each grade—as well as ACT and Digital SAT test prep—so you can have access to all the learning help you need across middle and high school!

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