The differences between American English and British English when writing your dissertation

When you begin writing your dissertation, you will need to decide what style of English to use.

The most commonly used dialects are American English, British English and Australian English. Although these dialects follow many of the same rules, they also have some important differences – especially in relation to spelling.

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.

Basic spelling differences

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 enroll
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
Past-tense verbs
US UK Australia
canceled cancelled cancelled
channeled channelled channelled
labeled labelled labelled
modeled modelled modelled
traveled travelled travelled
US UK Australia
acknowledgment acknowledgement (either)
aluminum aluminium aluminium
artifact artefact artefact
behavior behaviour behaviour
caliber calibre calibre
center centre centre
color colour colour
cooperation co-operation (either)
councilor councillor councilor
counselor counsellor counselor
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
Did you know?

Scribbr editors correct an average of 150 errors per 1,000 words? Prevent your thesis, essay or paper from being rejected based on language. Have it proofread by Scribbr’s language experts!

Discover the proofreading service

Don’t forget: Consistency is key!

Each word should of course be spelled the same throughout your document. However, it’s also important not to use a mix of English styles.


The defense minister first travelled to China in 2013. (US English/UK English)

The defense minister first traveled to China in 2013. (all US English)

The defence minister first travelled to China in 2013. (all UK English)

In addition, the same spelling should generally be used for all forms of a word.


US English: The organization is headquartered in Osaka, but it usually organizes workshops in Tokyo.

UK English: The colours of the samples varied greatly, but smallest sample was the most colourful.

Which type of English should I choose?

Some universities have a preference, so you may wish to check your school’s website for guidance. If you are free to decide yourself, it’s best to pick the style that feels most natural to you. Once you have done so, make sure you set the correct proofing language for your document (in Microsoft Word, select “Review” and then “Language”).

Further understanding the differences

If you want to know more about spelling and other grammatical differences between these English styles, see the table below. Bear in mind that the rules are not always very firm: there are many exceptions, and the preferred conventions are constantly changing!

Spelling: As can be seen, the variation usually relates to only one or two letters.

# US UK Australia
a uses -ize, -yze (e.g. quantize, analyze) prefers -ise, -yse (e.g. quantise, analyse), but is flexible almost always uses ise, yse
b -er (e.g. center, meter, etc.) -re (e.g. centre, metre, etc.) British usage
c uses -or (e.g. honor, color, splendor) uses -our (e.g. honour, colour, splendour) British usage
d uses –ction (e.g. connection) acceptable to use –xion (e.g. connexion) American usage
e prefers single consonants (e.g. canceled, focuses, appal), with certain exceptions for words in which the stressed syllable falls on the doubled consonant (e.g. willful) uses double consonants (e.g. focusses, cancelled, appall), with certain exceptions (e.g. wilful) British usage
f often drops -e for word modifications (e.g. judge à judgment, live à livable) generally keeps e for word modifications (e.g. judge à judgementlive à liveable) keeps -e: (e.g. judgement), like British; but sometimes drops -e: (e.g. livable)
g -e usually preferred to -oe or -ae (e.g. pediatrician, leukemia, etc.) -oe and -ae used (e.g. paediatrician, leukaemia, etc.) British usage

Punctuation: Here, the main differences relate to whether to use single or double quotation marks and where to place other punctuation in relation to those quotation marks.

# US UK Australia
a Double quotation marks (“x”), but alternate with single for quotations within quotations (e.g. She said, “This model has been called ‘the best.’”) Single quotation marks (‘x’), but alternate with double for quotations within quotations (e.g. She said, ‘This model has been called “the best”’.) UK usage
b Punctuation appears within quotation marks (e.g. “The best there is,” she said. or She said, “the best there is.”) except when punctuation emphasizes the writer’s sentence rather than the speaker’s quotation (e.g. Did she say, “the best there is”? or She told them we are “the best there is”!) Punctuation appears outside quotation marks, except when the punctuation is part of the original quotation (e.g. ‘The best there is’, she said. but She said, ‘the best there is.’; also, Did she say, ‘the best there is’? but She asked, ‘the best there is?’) UK usage

Verb forms: The different styles of English do not always agree about whether collective nouns should take singular or plural verbs. There is also disagreement about some past-tense forms of verbs.

# US UK Australia
a Collective nouns (nouns referring to a group of individual things) take verbs as conjugated for singular nouns (e.g. The team is going to win. or The staff has decided. or The team leads the charge.) Collective nouns (nouns referring to a group of individual things) take verbs as conjugated for plural nouns (e.g. The team are going to win. or The staff have decided. or The team lead the charge.) US usage
b Verbs take -ed endings for simple past tense and past participles (e.g. compel à compelled,spell à spelled,learn à learned) with the exception of common irregular verbs (e.g. take à took, hear à heard)  Verbs take -ed endings for simple past tense and past participles, but with more exceptions (e.g.compel à compelled but spell à spelt,learn à learnt); irregular verbs are conjugated the same UK usage

Abbreviations: There is also disagreement over how to use periods in abbreviations.

US UK Australia
Most title abbreviations take a period (e.g. Doctor à Dr. Missus à Mrs. Honorable à Hon. Avenue à Ave.) Title abbreviations take a period only if the abbreviation does not end on the last letter of the full word (e.g. Doctor à Dr Missus à Mrs butHonourable à Hon. Avenue à Ave.) UK usage
Is this article helpful?
Bas Swaen

Bas is co-founder of Scribbr. Bas loves to teach and is an experienced thesis writer. He tries to help students with writing clear and easy to comprehend articles about difficult topics.

Your dissertation without language mistakes and blunders?

Get help from a professional Scribbr editor.
More info & rates »
Trustpilot score of 9.8


Ally B
February 24, 2018 at 7:48 PM

Thanks for this. FYI - a spelling mistake (typo) appears in your first listed table:
"hypothesize | hypothesise|hyphothesise" - the third instance (Australian spelling) has an errant 'h' after the 'p'.
You're welcome!


Leon (Scribbr-team)
February 26, 2018 at 1:44 PM

Hi Ally,

We'll change that. :)



Francisco Sousa
February 16, 2018 at 3:50 AM

Thank this amazing thesis


June 16, 2016 at 8:00 PM

Thank you, this was amazing.


Comment or ask a question.