그래
geurae · TOPIK 1
yeah, right, okay
geurae sounds like agree-ay: you agree, so you say yeah, okay
그래 comes from 그렇다 (to be so, to be like that), from 그 (that) + 러하다. Saying it literally means it is so. The sound geu-rae echoes the gree in agree, which is exactly what the word does.