Source : https://www.howtostudykorean.com/unit0/197-2/#03 When ㅢ is found in the first syllable of a word, and the syllable begins with “ㅇ” (making the first sound be “ㅢ), the pronunciation is “ㅢ.” When ㅢ is found in the first syllable of a word, but the syllable begins with a consonant, the pronunciation can be “이.” When ㅢ is found somewhere other than the first syllable of a word, the pronunciation can be “이.” - when it's at the beginning of the word, it's pronounced 의 {ui} - if it's used at the end of the word as a possessive marker, it's usually pronounced as 에 {eh}. However, some Koreans pronounce it 의 {ui} in this case too - If it's the end syllable of a word, it's normally pronounced 이 {long e} As an example, 민주주의의 의의 (democracy's meaning/significance) is pronounced {민주주이에 의이}.