There is no deformation in British English. American English can put /r/ after vowels, while British English /r/ can only be used as voiced consonants. Used in American English? /,almost all British English uses /a:/. For example, no bel canto /k Nt/ British accent /ka: nt/, or dancing bel canto /d? Ns/ British pronunciation /da: ns/.
origin
American English originated from English in the era of Elizabeth I, and its history is closely related to the history of American immigration, dating back more than 300 years. 1607, the first colonists, including John Smith, crossed the Atlantic Ocean in three big ships and established Jamestown at the mouth of James River in Virginia.
Soon after, 1620, Puritans from Norfolk and Suffolk in the east of England arrived in Plymouth in the southeast of Massachusetts on the ship "Mayflower" and established a colony. At that time, Britain was in the period of Elizabeth I, and it was in the early stage of modern English from the perspective of English development history.
Among the first pilgrims who moved to New England, more than 100 were graduates from Oxford University and Cambridge University. They brought Elizabeth I's English to the New World of North America and became the starting point of American English. Since then, both countries have spoken Elizabethan English. Therefore, there is no significant difference between American English and British English for a long time.