UK vs. US English | Difference, Spelling & Examples
When writing your dissertation, research paper or essay, you will have to consistently follow the conventions of a specific style of English. The most commonly used forms are:
- American English
- British English
- Australian English
Although these dialects follow many of the same rules, they also have some important differences in spelling, punctuation and word choice.
US vs. UK spelling
As the table below shows, the difference between UK and US spelling usually relates to just one or two letters.
| US | UK | Australia |
|---|---|---|
| uses -ize, -yze (e.g., realize, analyze) | prefers -ise, -yse (e.g., realise, analyse), but is flexible | almost always uses ise, yse |
| -er (e.g., theater, meter) | -re (e.g., theatre, metre) | British usage |
| uses -or (e.g., honor, color, splendor) | uses -our (e.g. honour, colour, splendour) | British usage |
| uses –ction (e.g., connection) | acceptable to use –xion (e.g., connexion), but this is increasingly rare | American usage |
| often drops -e for word modifications (e.g., judge to judgment, live to livable) | generally keeps e for word modifications (e.g., judge to judgement, live to liveable) | keeps -e (e.g., judgement), like British; but sometimes drops -e (e.g., livable) |
| usually prefers -e to -oe or -ae (e.g., pediatrician, leukemia) | uses -oe and -ae (e.g., paediatrician, leukaemia) | British usage |
| usually prefers one “l” to double “ll” (e.g., canceled, traveled) | uses double “ll” instead of one “l” “(e.g., cancelled, travelled) | British usage (travelling vs |
The following cheat sheet outlines the preferred spelling of some words that are commonly used in academic writing.
| US | UK | Australia |
|---|---|---|
| analyze | analyse | analyse |
| apologize | apologise | apologise |
| capitalize | capitalise | capitalise |
| categorize | categorise | categorise |
| characterize | characterise | characterise |
| colonize | colonise | colonise |
| endeavor | endeavour | endeavour |
| enroll | enrol | enrol |
| fulfill | fulfil | fulfil |
| globalize | globalise | globalise |
| honor | honour | honour |
| hypothesize | hypothesise | hypothesise |
| inquire | enquire | enquire |
| install | instal | install |
| legalize | legalise | legalise |
| maneuver | manoeuvre | manoeuvre |
| maximize | maximise | maximise |
| minimize | minimise | minimise |
| mold | mould | mould |
| neutralize | neutralise | neutralise |
| optimize | optimise | optimise |
| paralyze | paralyse | paralyse |
| plow | plough | plough |
| privatize | privatise | privatise |
| randomize | randomise | randomise |
| realize | realise | realise |
| recognize | recognise | recognise |
| US | UK | Australia |
|---|---|---|
| canceled | cancelled | cancelled |
| channeled | channelled | channelled |
| labeled | labelled | labelled |
| modeled | modelled | modelled |
| traveled | travelled | travelled |
| US | UK | Australia |
|---|---|---|
| acknowledgment | acknowledgement | acknowledgment or acknowledgement |
| aluminum | aluminium | aluminium |
| artifact | artefact | artefact |
| behavior | behaviour | behaviour |
| caliber | calibre | calibre |
| center | centre | centre |
| color | colour | colour |
| cooperation | co-operation | cooperation or co-operation |
| councilor | councillor | councillor |
| counselor | counsellor | counsellor |
| defense | defence | defence |
| estrogen | oestrogen | oestrogen |
| fetus | foetus | foetus |
| fiber | fibre | fibre |
| flavor | flavour | flavour |
| humor | humour | humour |
| judgment | judgement | judgement |
| labor | labour | labour |
| leukemia | leukaemia | leukaemia |
| license | licence | licence |
| liter | litre | litre |
| meter | metre | metre |
| neighbor | neighbour | neighbour |
| organization | organisation | organisation |
| paleontology | palaeontology | palaeontology |
| program | programme (but program if computer-related) | program |
| sulfur | sulphur | sulphur |
| theater | theatre | theatre |
| tire | tyre | tyre |
| vapor | vapour | vapour |
| US | UK | Australia |
|---|---|---|
| aging | ageing | ageing |
| favorite | favourite | favourite |
| gray | grey | grey |
| livable | liveable | livable |
| movable | moveable | moveable |
| orthopedic | orthopaedic | orthopaedic |
| salable | saleable | saleable |
| skeptical | sceptical | sceptical |
| somber | sombre | sombre |
US vs. UK punctuation
The main punctuation differences relate to single and double quotation marks and where to place other punctuation in relation to quotations.
| US | UK | Australia |
|---|---|---|
Double quotation marks (“x”), but alternate with single for quotations within quotations
|
Single quotation marks (‘x’), but alternate with double for quotations within quotations
|
UK usage |
Punctuation appears within quotation marks…
… except when punctuation emphasizes the writer’s sentence rather than the speaker’s quotation
|
Punctuation appears outside quotation marks…
…except when the punctuation is part of the original quotation rather than the speaker’s sentence.
|
UK usage |
US vs. UK verb conjugation
There are some differences in subject-verb agreement with collective nouns (nouns referring to a group of individual things as a unified whole) and in past tense verb forms.
| US | UK | Australia |
|---|---|---|
Tends to treat collective nouns as singular.
|
Tends to treat collective nouns as plural.
|
US usage |
Verbs take -ed endings for simple past tense and past participles…
… with the exception of common irregular verbs
|
Verbs take -ed endings for simple past tense and past participles, but with more exceptions…
… and irregular verbs are conjugated the same
|
UK usage |
US vs. UK abbreviations
There is also disagreement over how to use periods in abbreviations.
| US | UK | Australia |
|---|---|---|
Most title abbreviations take a period.
|
Title abbreviations take a period only if the abbreviation does not end on the last letter of the full word
|
UK usage |
Consistency is key
Most importantly, each individual word must be spelled the same throughout your document. However, it’s also best to avoid mixing US English and UK English.
- The defense minister first travelled to China in 2013.
- The defense minister first traveled to China in 2013.
- The defence minister first travelled to China in 2013.
In addition, the same spelling should generally be used for all forms of a word.
- The organization is headquartered in Osaka, but it usually organises workshops in Tokyo.
- The organization is headquartered in Osaka, but it usually organizes workshops in Tokyo.
- The organisation is headquartered in Osaka, but it usually organises workshops in Tokyo.
If you use our proofreading and editing service, you can request a specific style of English (US or UK).
Why is it so complicated?
After winning their independence from the British, Americans used language as a way to create their own identity. This led to many variations in spelling and punctuation, among other things. Australia also developed its own written conventions, which lie somewhere between those of the US and the UK (although they tend to be more British).
Of the three, Australian English is generally the most flexible, and US English is the least flexible. Bear in mind that the rules are not always very firm: there are many exceptions, and the preferred conventions are constantly changing.