Pour-poor and cure-fir mergers
In the most conservative varieties of Received Pronunciation and General American, CURE words are pronounced with RP ( before a vowel) and GenAm . But these pronunciations are being replaced by other pronunciations in many English accents.
In English English it is very common to pronounce CURE words with , so that moor is often pronounced , tour , poor , (Wells 1982: 56, 65–66, 164, 237, 287–88). A similar merger is encountered in many varieties of American English, where the pronunciations / (depending on whether the accent is rhotic or non-rhotic) or prevail. (Kenyon 1951: 233–34; Wells 1982: 549).
In East Anglia a merger with the of shirt is common, especially after palatal and palatoalveolar consonants, so that sure is often pronounced ; yod dropping may apply as well, yielding pronounciations such as for pure. Similarly in American English sure is often pronounced (Wells 1982: 164). Other American pronunciations showing this merger include pure, curious, bureau, mural (M. Hammond 1999: 52).