I've been reading up about the Yanbian dialect of Korean, and came across the concept of vowel harmony in this article. https://www.korean.go.kr/nkview/nklife/1998_4/8-8.html
e.g. 모두 = 모도, 배우다 = 배오다, 깨끗하다 = 깨갓하다, 가게 = 가개
Does this apply to all words? If not, when/how is it used?
Does it apply to the entirety of a word or just the vowel right after?
e.g. if 한국 = 한곡, then 대한민국 = 대한민곡 or 대한민국?
If it applies to the entirety, does that include any particles attached to it?
e.g Standard Korean 배우고 싶다 in Yanbian/Hamgyeong Korean is 배오구 싶다. Would this be pronounced colloquially as 배오고 싶다? 한국에 = 한곡에 or 한곡애 ?
There is also the concept of umlaut in the Korean dialect, especially with i.
e.g. 당기다 = 댕기다, 어미 = 에미
Is this always used?
e.g. 합니다 = 햄니다?
But I don't know how this is used when it comes to vowel harmony. Are both used? Or is a vowel which changes because of harmony not affected by umlaut?
e.g. 아버지 = 아바지 or 아배지? 환영 = 환양, 홴양, or 홴영?
If anyone has any ideas, that would be great