내 동생이

my younger sibling

→ 내
phrase Rare #21,897
my younger sibling 내 means “my,” 동생 means “younger sibling,” and 이 is the subject marker. Depending on context, 동생 can mean a younger brother or younger sister.
KO: 내 동생이 오늘 집에 와.
EN: My younger sibling is coming home today.

내 동생이 수녀 였는데 젊었을 때 죽었어

My younger sibling was a nun, but she died young.

— 8과 1/2 (1963)

내 동생이 어떤 사람 이었는지

What my younger sibling was like

— 맥시멈 리스크 (1996)

내 동생이 죽었다

My younger sibling died.

— 리전에어 (1998)