ㅡ
으 (eu)
No English twin: say “oo” but keep your lips spread flat, as if smiling.
StrokesOne stroke: a single line from left to right.
Easy to confuseㅜ — Add a dash below and it's ㅜ, with rounded lips.
Examples
그림
geurim
picture
크다
keuda
big
음악
eumak
music