English phonology is the stuy of the phonology (i.e. the sound system) of the English language. Like all languages, spoken English has wide variation in its pronunciation both diachronically and synchronically from dialect to dialect. This variation is especially salient in English, because the language is spoken over such a wide territory, being the predominant language in Australia, Canada, the Commonwealth Caribbean, Ireland, New Zealand, the United Kingdom and the United States in addition to being spoken as a first or second language by people in countries on every continent, and notably in South Africa and India. In general the regional dialects of English are mutually intelligible.