British English is the standard dialect of English language as spoken and written in the United Kingdom. Variations exist in formal, written English in the United Kingdom. For example, the adjective wee is almost exclusively used in parts of Scotland and Ireland, and occasionally Yorkshire, whereas little is predominant elsewhere. Nevertheless, there is a meaningful degree of uniformity in written English within the United Kingdom, and this could be described by the term British English. The forms of spoken English, however, vary considerably more than in most other areas of the world where English is spoken, so a uniform concept of British English is more difficult to apply to the spoken language. According to Tom McArthur in the Oxford Guide to World English, British English shares "all the ambiguities and tensions in the word 'British' and as a result can be used and interpreted in two ways, more broadly or more narrowly, within a range of blurring and ambiguity".
When distinguished from American English, the term "British English" is sometimes used broadly as a synonym for the various varieties of English spoken in some member states of the Commonwealth of Nations.
English is a West Germanic language that originated from the Anglo-Frisian dialects brought to Britain by Germanic settlers from various parts of what is now northwest Germany and the northern Netherlands. The resident population at this time was generally speaking Common Brittonic—the insular variety of continental Celtic, which was influenced by the Roman occupation. This group of languages (Welsh, Cornish, Cumbric) cohabited alongside English into the modern period, but due to their remoteness from the Germanic languages, influence on English was notably limited. However, the degree of influence remains debated, and it has recently been argued that its grammatical influence accounts for the substantial innovations noted between English and the other West Germanic languages.
Initially, Old English was a diverse group of dialects, reflecting the varied origins of the Anglo-Saxon Kingdoms of England. One of these dialects, Late West Saxon, eventually came to dominate. The original Old English language was then influenced by two waves of invasion: the first was by speakers of the Scandinavian branch of the Germanic family, who conquered and colonised parts of Britain in the 8th and 9th centuries; the second was the Normans in the 11th century, who spoke Old Norman and ultimately developed an English variety of this called Anglo-Norman. These two invasions caused English to become "mixed" to some degree (though it was never a truly mixed language in the strictest sense of the word; mixed languages arise from the cohabitation of speakers of different languages, who develop a hybrid tongue for basic communication).
The more idiomatic, concrete and descriptive English is, the more it is from Anglo-Saxon origins. The more intellectual and abstract English is, the more it contains Latin and French influences e.g. swine (like the Germanic schwein) is the animal in the field bred by the occupied Anglo-Saxons and pork (like the French porc) is the animal at the table eaten by the occupying Normans.
Cohabitation with the Scandinavians resulted in a significant grammatical simplification and lexical enrichment of the Anglo-Frisian core of English; the later Norman occupation led to the grafting onto that Germanic core of a more elaborate layer of words from the Romance branch of the European languages. This Norman influence entered English largely through the courts and government. Thus, English developed into a "borrowing" language of great flexibility and with a huge vocabulary.