face, bacon. However, some accents, in the north of England and in Scotland, for example, retain a monophthongal pronunciation of this vowel, while other accents have a variety of different diphthongs. Before (historic) /r/, in words like square, the vowel has become (often practically ) in modern RP, and in General American. Changes in realization of Independently of the development of the long vowel, the short came to be fronted and raised to . This change was mostly confined to "vulgar or popular" speech in the 16th century, but it gradually replaced the more conservative in the 17th century, and was "generally accepted by careful speakers by about 1670". This vowel (that of trap, cat, man, bad, etc.) is now normally denoted as . In present-day RP, however, it has lowered to a fully front . Such a quality is also found in the accents of northern England, Wales, Scotland, Ireland, and the Caribbean. Raised pronunciations are also found in Southern Hemisphere English, and are also associated with Cockney. For the possibility of phonemic length differentiation, see bad–lad split, below. Development of the new long A In Modern English, a new phoneme developed that did not exist in Middle English. The phoneme comes from three sources: the word father lengthening from to for an unknown reason (thus splitting from gather); the compensatory lengthening of the short in words like calm, palm, psalm when was lost in this environment; and the lengthening of before in words like car, card, hard, part, etc. In most dialects that developed the broad A class, words containing it joined this new phoneme as well. The new phoneme also became common in onomatopoeic words like baa, ah, ha ha, as well as in foreign borrowed words like spa, taco, llama, drama, piranha, Bahamas, pasta, Bach, many of which vary between and among different dialects of English. Some of these developments are discussed in detail in the following sections. Before /r/ In late Middle English, pairs such as cat, cart, were pronounced , respectively, distinguished only by the presence or absence of . However, by the late 17th century they were also distinguished by the quality and length of the vowel. In cat, the vowel had been fronted to , while in cart it had been lengthened to . This latter change seems to have first occurred in the dialects of southern England in the early 15th