There are not a great many differences between British and American styles of spelling. Further, the differences are not respected consistently in the USA or the UK. They generally result from spelling reform attributable to Noah Webster and the dictionary of American words that he completed in 1828 or to the National Education Association in the US:
The main differences in spelling between American and British writing can be summarized are as follows:
- American words that end in -er (e.g., center, fiber, theater) often end in -re (e.g. centre, fibre, theatre) in -er in British English.
- American words that end in -or (e.g., color, humor, flavor) usually end in -our
(e.g. colour, humour, flavour) in British English.
- Verbs that end in a vowel plus l in American spelling, use an additional l in British spelling when an ending that begins with a vowel is added (e.g., model, modelled, modeler in the UK vs. model, modeled, modeler in the US).
- Words that are spelled with the double vowels ae or oe (e.g., archaeology, manoeuvre) in British English use only e in American English (e.g., archeology, maneuver).
- The directional suffix -wards used in British English (e.g., forwards, towards, rightwards) are usually spelled without an s in American English (e.g., forward, toward, rightward).
- ome nouns that end in British English with -ence (e.g., defence, licence) are spelled with -ense in American English (e.g., defense, license).
- In British spelling, some nouns that end with -ogue (e.g., analogue, dialogue) end with -og in American English (e.g., analog, dialog).
- In British English, verbs that can be spelled with either -ize or -ise as the ending (e.g., organise/organize) use only -ize in American English (e.g., organize). The same is true for the nouns and adjectives derived from these verbs. Therefore, organization in British English becomes organization in American English.
- Similarly, verbs that end in -yse (e.g., analyse) in British English end in -yze in American English (e.g., analyze).
- There are other differences between British and American spelling of the past participles of verbs. There are three main groupings:
- Verbs that use -ed or -t for the simple past and past participle. In general, if the verb has an -ed form, it will be used in American English (e.g., dreamed, leaped, learned). If there is a -t verb form, it will be used in British English (e.g., dreamt, leapt, learnt).
- Verbs that use for the simple past tense either the base form of the verb or the ending -ed (e.g., American fit, knit, forecast, wed vs. British fitted, knitted, forecasted, wedded).
- Verbs that for the simple past tense have an irregular spelling or an -ed ending (e.g., lit, strove in American spelling vs. lighted, strived in British spelling).