Although the American English developed from British English, there are some important differences between the two. The choice between American and British usage should be based on the culture and preference of your target readers.

Problems arise when writers make use of both writing styles in one text. As with grammar and word errors, inconsistent use of the styles distracts the reader from the message content. People from some countries, such as India, often have difficulty writing straight in one style, having been raised and educated in UK English but being exposed to US English in international business and entertainment.

Some examples of the spelling differences between UK and US English (this list is not exhaustive):
-t forms – UK usage has some irregular words such as burnt, dreamt, whilst, amidst, and amongst; US English prefers the forms burned, dreamed, while, amid, and among.
-ue forms – Have a dialogue on your analogue cellular phone with your British friends, but have a dialog on your analog cellular phone with your American friends.
-tre forms – The Brits go the centre of the theatre, while the Yanks go to the center of the theater.
-ce forms – The British coach tells his players to employ good offence and defence; the American coach encourages good offense and defense.
-z forms – UK English has a lot of –s verbs: apologise, analyse, and specialize; US English uses the –z verbs: apologize, analyze, and specialize.
-ou forms – Honour your neighbor in London, but honor your neighbor in New York.
Other forms – tyre for tire, draught for draft, grey for gray, cheque for check, and many more.

UK and US English differ in usage as well (once again, this list is not exhaustive):
Periods – In UK usage, periods are usually not used in abbreviations, such as in AD, eg, etc, Dr, Mrs, and so on.
Hyphens – The Brits use a hyphen to separate a prefix ending with a vowel from a word beginning with the same vowel: co-operation for cooperation, pre-eminent for preeminent, and so on.
Subject-verb agreement – Some nouns that are singular in US English may be used both as singular and plural in UK English. For example, in UK usage, “The government is/are optimistic” are both acceptable; in US usage, only “The government is optimistic” is acceptable.
Vocabulary – lift (UK) for elevator (US), flyover for overpass, petrol for gasoline, tinned for canned, flats for apartments, and many, many more.

inWrite's writers and editors are adept in both US and UK English. Please visit our Proofreading Services page or Writing Services page for more information.