“Long” vowels

BATH, PALM, START

Simplifying matters a bit, the three main variants of the BATH vowel can be regarded as shibboleths of major L1 accents: a low back and long [ɑ:] of southern EngE and RP, a low front [a] of northern EngE, and a front and slightly raised [æ] of AmE. In Britain, transition areas and the south-west show mixed types, in particular with respect to length. In America, low variants are associated with Boston and New England, and are common in many parts of the Caribbean; other types found include raised (mainly in the North) and offgliding (mainly in the South) pronunciations, as well as forms with varying length. Australia and New Zealand tend to side with southern England here, although lower-class and eastern accents of AusE have a widely-noted [æ] in such words, and NZE has a central and slightly raised [ɐ] variant. Most South African and South Asian accents also prefer the RP variant, as do the South-East Asian varieties with respect to quality but with a shorter realization. On the other hand, most parts of West and East Africa and the Pacific varieties prefer the [a] variant, while LibSE follows AmE.

For PALM and START, there is variability between back (predominant in North America, South Africa and Asia) and front (strong in parts of Britain and dominant in West and East Africa) realizations; the Caribbean has both, and in Australia and New Zealand the quality tends to be rather central. The vowels are usually long, though shortening is possible in some dialects; off-gliding occurs relatively rarely (in some dialects of AmE and, socially conditioned, AusE).