▁ <0xE3> <0x85> <0x90> ▁[ æ ], ▁ <0xE3> <0x85> <0x94> ▁[ e ], ▁ <0xE3> <0x85> <0x9A> ▁[ ø ], ▁ <0xE3> <0x85> <0x9F> ▁[ y ] ▁with ▁only ▁an ▁exception : ▁ <0xE3> <0x85> <0xA2> . ▁However , ▁in ▁late ▁modern ▁Korean , ▁ <0xE3> <0x85> <0x9F> ▁is ▁di ph th ong ized ▁to ▁[ wi ]. ▁Also , ▁ <0xE3> <0x85> <0x9A> ▁is ▁un stable ▁and ▁standard ▁Korean ▁allows ▁to ▁pron ounce ▁both ▁[ ø ] ▁and ▁[ we ]. ▁ ▁In ▁modern ▁Korean ▁language , ▁there ▁are ▁two ▁types ▁of ▁I - mut ation , ▁or ▁I - ass im ilation : ▁I - forward - ass im ilation ▁( <0xE3> <0x85> <0xA3> ▁ 순 행 ▁ 동 화 ) ▁and ▁I - back ward - ass im ilation ▁( <0xE3> <0x85> <0xA3> ▁ 역 행 ▁ 동 화 ). ▁Ass im ilation ▁is ▁occurred ▁when ▁ <0xE3> <0x85> <0xA3> ▁is ▁in ▁front ▁( forward ) ▁or ▁behind ▁( back ward ) ▁of ▁the ▁sy ll able . ▁In ▁standard ▁Korean , ▁only ▁a ▁few ▁words ▁are ▁allowed ▁to ▁assim il ate , ▁however , ▁exceptions ▁are ▁often ▁observed ▁in ▁some ▁dialect s ▁and ▁caus al ▁usage . ▁I - forward - ass im ilation ▁adds ▁[ j ] ▁sound , ▁but ▁I - back ward - ass im ilation ▁causes ▁v owel ▁to ▁um la ut . ▁ ▁For ward : ▁ 피 어 ▁( to ▁blo om ) ▁[ pi . ə ] ▁→ ▁ 피 여