Standard variety is the variety of a language which has the highest status in a community or nation and which is usually based on the speech and writing of educated native speakers of the language. A standard variety is generally: used in the news media and in literature; described in dictionaries and grammars; taught in school and taught to non-native speakers when they learn the language as a foreign language. A standard variety may contain some variation in pronunciation according to the part of the country where it is spoken, e.g. Standard British English in Scotland, Wales, Southern England.
Standard English is sometimes used as a cover term for all the national standard varieties of English. These national standard varieties have differences in spelling, vocabulary, grammar, and particularly pronunciation, but there is a common core of the language. This makes it possible for educated native speakers of the various national standard varieties of English to communicate with one another.
The British accept and enjoy the class distinctions. And these class distinctions influence people's speech greatly. The way English is spoken helps to identify not only the region that one lives in, but the class status too. Since the days of Shakespeare the English of South-East England has been considered "the standard", and by the way the South-East is the region of economic and political power.
Many people in England possess so called Received Pronunciation (RP), derived from the public school system attended by the boys from rich families. RP remains the accent of the elite. There are two kinds of RP. One is "unmarked" RP, which suggests no more that the speaker is well educated. This is the dialect of the BBC. Through radio and television "unmarked" RP is becoming more and more widely spoken accent. Then there is "marked" RP, which indicates high social class and is spoken by many army officers who come from upper class families. Although spoken by less than 5% of the population, RP has great influence and social authority.
Regional accents are also often spoken in Britain. Scottish, Welsh and Irish are generally the most popular regional accents. Then come Northern and West country accents and then - the least popular urban accents of London, Liverpool, Glasgow. It is interesting to notice that the television news is usually read by RP speakers, while the weather forecast following the news is often read by someone with a regional accent.
English in the USA differs considerably from British English. Pronunciation is the most striking difference but there are also a number of differences in vocabulary and spelling as well as slight differences in grammar. On the whole British people are exposed to a lot of American English on TV, in films, in literature and so they will usually understand most American vocabulary. Examples: British: colour, centre, practice. American: color, center, practise. But American English and British English are not too separate languages. It is one language in different variations. American English is not the only special variety of English. Each area of the English-speaking world has developed its own special characteristics, its own vocabulary and pronunciation characteristics.
Australian English is particularly interesting for its reach store of highly colloquial words and expressions. Australian colloquialism often involves shortening a word. Sometimes the ending "ie" is changed into "o". Instead of "smokie" they say "smoko". Instead of "beautiful" they often say simply "beaut". Because of current popularity of Australian TV-programs and films some of these words are now being used by British people, too.
Scottish English uses a number of special dialect words. For example lake - loch; mountain - ben; church - kirk; to remember - to mind; beautiful - bonny; to live - to stay; a girl - lassie; no - ken.