엄마가 얼마나

how ... mom

→ 엄마
phrase Rare #32,043
how ... mom Introduces a phrase describing the degree or extent of something about Mom; the predicate that completes the meaning comes after 얼마나.
KO: 엄마가 얼마나 기뻐했는지 몰라.
EN: You wouldn’t believe how happy Mom was.

로사 엄마가 얼마나 들떠 있는지 많이 변했어

Rosa’s mom has changed a lot—she’s so much more upbeat now.

— 내 어머니의 모든 것 (1999)