Welsh English, but this does not affect the upper-class southern accent that developed into Received Pronunciation, nor does it affect the far north of England or East Anglia. After World War II Some of these changes are in progress. Restoration of post-vocalic in some non-rhotic accents of Southern American English Changes to the low front vowel /æ/ raising: raising, lengthening or diphthongization of in some varieties of American English in particular contexts, especially before nasal consonants, resulting in . Some linguistics research suggests that /æ/ raising existed since the American colonial era, due to relic evidence of this feature in some of the Northern and Midland U.S. Bad–lad split: the lengthening of to in some words, found especially in Australian English and to a degree in Southern English English. Raising to in New Zealand and South African English. Lowering to in Received Pronunciation, Canadian English, and Western American English (except before nasal consonants). Lock–loch merger: the replacement of with among some younger Scottish English speakers from Glasgow Annexe 4: Linguistic Variables, Department of Language and Linguistics | University of Essex. Pin–pen merger: the raising of to before nasal consonants in Southern American English and southwestern varieties of Hiberno-English. Horse-hoarse merger /ɔr/ and /or/ merge in many varieties of English Vowel mergers before intervocalic /r/ in most of North America (resistance occurs mainly on the east coast): Mary–marry–merry merger: /eɪr/ and /ær/ merge to /ɛr/. Hurry-furry merger: /ʌr/ and /ɜr/ merge to /ɚ/. Mirror-nearer merger /ɪr/ and /ir/ merge or are very similar, the merged vowel can be quite variable. Fronting of back vowels: In many varieties of English, is fronted to , , or Resistance occurs in Northern American English and New York City English. In British English and some American English, is fronted to , , or Resistance occurs in Northern American English and New York City English. In many varieties /ʌ/ is fronted to [ʌ̟], [ɜ], or [ɐ]. T-glottalization becomes increasingly widespread in Great Britain. Various treatments of the th sounds, the dental fricatives : Th-fronting: merger with the labiodental fricatives Th-stopping: shift to dental stops , or merger with alveolar stops Th-debuccalization: lenition to Th-alveolarization: merger with alveolar fricatives L-vocalization: changes to an approximant or vowel, such as , or . This occurs in Estuary English and other dialects. Yod-dropping: loss of in some consonant clusters. Though it occurs in some environments in many British English dialects,