How do northern and southern Ukrainian dialects differ in vowels
The main difference between northern and southern Ukrainian dialects in terms of vowels lies in how old vowels ě, o, and e have changed under accentuation. In the northern dialects, these vowels transformed to the i sound only under stressed conditions (e.g., “did” from “dědъ” - old man), while in the southern dialects this vowel change occurred regardless of stress (e.g., “lis” and “lisý” both for forest).
Additionally, northern dialects have archaic vocalism of stressed vowels, often using monophthongs for letters “о” and “е” when stressed, and a sound shift where unstressed “а” may sound similar to standard “е” after a palatalized consonant. Southern dialects show more uniform vowel change in stressed and unstressed syllables.
Thus, the key vowel difference is in the role of accentuation in vowel mutations and the preservation of older vowel forms in the north versus more widespread vowel changes in the south. 1, 2, 3
Other dialectal differences also include some vocabulary and phonetic traits but accent-dependent vowel changes are the core distinguishing feature between northern and southern Ukrainian dialects. 2, 4