Phonological History of English Vowels - Diphthongs

Diphthongs

• The vein–vain merger is the merger of the Middle English diphthongs /ai/ and /ei/ that occurs in all dialects of present English.
• The following mergers are grouped together by Wells as the long mid mergers. They occur in all but a few dialects of English.
  • The pane–pain merger is a merger of the long mid monophthong /eː/ and the diphthong /ɛi/.
  • The toe–tow merger is a merger of the Early Modern English vowels /oː/ and /ɔu/.
• The cot–coat merger is a phenomenon occurring for some speakers of Zulu English where the phonemes /ɒ/ and /oʊ/ are not distinguished.
• The rod–ride merger is a merger of /ɑ/ and /aɪ/ occurring for some speakers of African American Vernacular English.
• The pride–proud merger is a merger of the diphthongs /aɪ/ and /aʊ/ before voiced consonants occurring for some speakers of African American Vernacular English.
• The line–loin merger is a merger between the diphthongs /aɪ/ and /ɔɪ/ that occurs in some English dialects.
• The coil–curl merger is a merger of /ɔɪ/ and /ɜr/ which historically occurred in some dialects of English. It is particularly associated with the dialects of New York and New Orleans.