Grammar
-기까지 하다
to even go so far as to do
Form
Verb stem + -기까지 하다 (“even go so far as to do”).
Function
Adds an action as an additional or extreme step, often presented as surprising or excessive.
Why this form?
-기도 하다 — “also do / sometimes do”: adds an activity or possibility; -기까지 하다 marks an extreme degree.
Forms not to confuse
-기도 하다
주말에는 운동하기도 해요. — I also exercise on weekends sometimes.
Examples
그는 지민에게 계속 상처 주는 말을 퍼붓고, 때리기까지 한다. — He keeps hurling hurtful words at Jimin and even goes so far as to hit him.
그는 거짓말을 하기까지 했어요. — He even went so far as to lie.