What is the origin of the different pronunciation of words like park, yard,
cartoon, margarine in American and British English?
In other words, why doesn’t British English generally pronounce the r in such words? Or vice-versa: why does American English generally pronounce the r in the same words?
Best Answer
Broadly, English accents are divided into two categories, rhotic and non-rhotic. All English accents were originally rhotic, and the R sound was typically articulated as an alveolar trill, in contrast with the alveolar approximant of most contemporary dialects. Non-rhotic accents began developing in the Middle English period, and were commonplace by the arrival of modern English, gaining popularity in southern England during the 18th century.
Both the British Isles and the United States, as well as Australia and other areas where English is spoken, have regions of both rhotic and non-rhotic accents. As Alex mentions, notable non-rhotic United States accents include coastal New England, New York, and old-style Deep Southern; the so-called "continental" or trans-Atlantic accent, characteristic of upper-class America through much of the 20th century, was also distinctly non-rhotic. Rhotic British accents are to be found in the West Country, as well as much of Scotland and Ireland.