British English and American English Spelling

Here are the principal differences in spelling between British English and American English.

	British English	American English
Final -l is always doubled after one vowel in stressed and unstressed syllables in English but usually only in stressed syllables in American English, for example:	rebel > rebelled travel > travelled	rebel > rebelled travel > traveled
Some words end in -tre in English and -ter in American English, for example:	centre theatre	center theater
Some words end in -ogue in English and -og in American English, for example:	analogue catalogue	analog catalog
Some words end in -our in English and -or in American English, for example:	colour labour	color labor
Some verbs end in -ize or -ise in English but only in -ize in American English, for example:	realise, realize harmonise, harmonize	realize harmonize

Common Differences

English

American English

all right

all right, alright (disputed)

analyse

analyze

centre

center

cheque

check

colour

color

counsellor

counselor

criticise, criticize

criticize

defence

defense

doughnut

donut

favour

favor

fibre

fiber

flavour

flavor

fulfil

fulfill

grey

gray

honour

honor

humour

humor

jewellery

jewellery, jewelry

judgement, judgment

judgment

kerb

curb

labour

labor

license, licence (verb) licence (noun)

license (verb) license (noun)

litre

liter

metre

meter

mould

mold

neighbour

neighbor

offence

offense

practise (verb) practice (noun)

practice (verb) practice (noun)

pretence

pretense

programme

program

pyjamas

pajamas

realise, realize

realize

savour

savor

speciality

specialty

theatre

theater

travelled travelling

travelled, traveled travelling, traveling

tyre

tire

valour

valor

Courtesy of : http://www.englishclub.com/writing/spelling_american-english.htm