Published online by Cambridge University Press: 27 June 2016
Although variants of the form [fri] and [bof] for standard [θri] ‘three’ and [boθ] ‘both’ are well attested in dialects as divergent as Cockney (Sivertsen 1960) and Black English Vernacular (Wolfram and Fasold 1974), there has been no attempt, to my knowledge, to treat these “substitutions” (a term with which they are frequently dismissed) as anything but isolated phenomena. Wyld (1936) and Dobson (1957), who are among the most respected authorities on English phonology, both specifically identify the [θ]/[f] alternation as an “isolative change.