얼마 전= a while ago few hours ago=몇 시간 전 earlier=이전

I wonder why no one mentioned 아까. o_O

a while ago - 좀 전에 a few hours ago - 몇 시간 전에 earlier - 이전에 earlier today isn't used in Korea, a while ago or this morning etc are used

I always hear 아까 to say "a while ago" or "earlier"