what has caused the differences between the British and English.doc

This is one of a series of articles about the differences between American English and British English, which, for the purposes of these articles, are defined as follows:
American English (AmE) is the form of English used in the United States. It includes all English dialects used within the United States.
British English (BrE) is the form of English used in the United Kingdom. It includes all English dialects used within the United Kingdom.
Written forms of American and British English as found in newspapers and textbooks vary little in their essential features, with only occasional noticeable differences parable media[1] (comparing American newspapers to British newspapers, for example). This kind of formal English, particularly written English, is often called 'standard English'.[2][3] An unofficial standard for spoken American English has also developed, as a result of mass media and geographic and social mobility, and broadly describes the English typically heard work newscasters, commonly referred to as non-regional diction, although local newscasters tend toward more parochial forms of speech. [16] Despite this unofficial standard, regional variations of American English have not only persisted but have actually intensified, according to linguist William Labov.
Regional dialects in the United States typically reflect the elements of the language of the main immigrant