Monophthongs and diphthongs  NEAR, SQUARE and CURE

The centring diphthongs found in Standard English NEAR, SQUARE and CURE all tend to be realized as monophthongs in closed syllables, but falling diphthongs in open syllables. Thus, years > [jis], tears > [tis], scared > [sket], Mary > [meri], insurance > [insurɐns] , during > [d^juriŋ] ; beer > [biɐ], swear > [sweɐ], insure > [insuɐ]. Each diphthong’s second target tends to be an extra short [ɐ]. There is a lot of variation in the articulation of the CURE vowel, especially in words like tour. This is seen in all other varieties of English as well. In many varieties the diphthong has coalesced into [ɔ], or is articulated as an [ɔə] glide. This extreme variation, or instability, is perhaps because the vowel of CURE is the least frequent of vocalic sounds.