Others
Labov, Ash, and Boberg (2006: 73) mention four mergers before /l/ that may be under way in some accents of North American English, and which require more study:
- /ʊl/ and /ol/ (bull vs bowl)
- /ʌl/ and /ɔl/ (hull vs hall)
- /ʊl/ and /ʌl/ (bull vs hull)
- /ʌl/ and /ol/ (hull vs hole)
Read more about this topic: English-language Vowel Changes Before Historic /l/