After 1900
Some of these changes are in progress.
- æ-tensing: raising, lengthening and/or diphthongization of /æ/ in some varieties of American English, especially before nasal consonants
- Bad–lad split: the lengthening of /æ/ to in some words, found especially in Australian English and to a degree in Southern English English.
- Lock–loch merger: the replacement of /x/ with /k/ among some younger Scottish English speakers from Glasgow, .
- Pin–pen merger: the raising of /ɛ/ to /ɪ/ before nasal consonants; can be found in Southern American English and southwestern varieties of Hiberno English.
- Back-vowel-fronting: in many varieties of English all over the world, /u/ and to a lesser extent /o/ are gradually moving forward in the mouth. (Compare casual pronunciation of "food" to .)
- T-glottalization becomes increasingly widespread in Great Britain. (Trudgill, pp. 77–78)
- Various treatments of th: Th-fronting, th-stopping, th-debuccalization and th-alveolarization
- L-vocalization in the south-east of England, including London. This is not unique to the south-east of England, however, and is found in many other dialects. (Trudgill, pp. 63–66)
- Yod-dropping losing /j/ in initial consonant clusters
- Northern cities vowel shift: raising and tensing of /æ/, fronting of /ɑ/, lowering of /ɔ/, backing and lowering of /ɛ/, backing of /ʌ/ and lowering and backing of /ɪ/ in Inland Northern American English
Read more about this topic: Phonological History Of English