경험 · have p.p.
I've been to Korea three times. (~해 본 적 있다)
경험 질문 · Have you ever p.p.?
Have you ever seen this movie?
한 번도 없다 · never p.p.
I've never heard of that.
완료 · just / already p.p.
I've just arrived. · I've already had lunch.
아직 · haven't p.p. yet
I haven't decided yet.
결과 · have lost
I've lost my keys. → 지금도 없음