North American English
There are a considerable number of different accents within the regions of both the United States and Canada, originally deriving from the accents prevalent in different English, Scottish and Irish regions of the British Isles and corresponding to settlement patterns of these peoples in the colonies. These were developed and built upon as new waves of immigration, and migration across the North American continent, brought new accents and dialects to new areas, and as these ways of speaking merged and assimilated with the population. It is claimed that despite the centuries of linguistic changes there is still a resemblance between the English East Anglia accents which would have been used by early English settlers in New England (including the Pilgrims), and modern Northeastern United States accents. Similarly, the accents of Newfoundland have some similarities to the accents of Scotland and Ireland.
Th-fronting
In 1988, it was noted as spreading amongst non-standard accents in England. Although "th"-fronting is found occasionally in the middle and upper (middle) class English accents as well, there is still a marked social difference between working and middle class speakers. "Th"-fronting is regarded as a 'boundary marker' between Cockney and Estuary English, as depicted in the first descriptions of the latter form of English and confirmed by a phonetic study conducted by researcher Ulrike Altendorf. Nevertheless, Altendorf points out that "th"-fronting is found occasionally in middle class (Estuary) speech as well and concludes that "it is currently making its way into the middle class English accent and thus into Estuary English".