"have"as a verb : 있다
돈이 있어요. have money
"don't have" as a verb : 없다
돈이 없어요. don't have money
" have + p.p. " as an auxiliary verb : V + 았/었/였 + 다
1. the word in front of the last word includes "ㅏ " or " ㅗ " -> V + 았다
2. the word in front of the last word don't includes "ㅏ " or " ㅗ " -> V + 었다
3. the word ends with " - 하다 " -> V + 였다 (Note that : 하+여->해)
for example:
eat 먹다 : 먹 + 었다 = 먹었다
have eaten : 먹었어요
go 가다 : 가 + 았다 = 갔다
have gone : 갔어요
study 공부하다 : 공부하+였다 = 공부했다
have studied : 공부했어요
" have + p.p. " as a auxiliary verb and the movement had already finished : V + 아/어/여 버렸다
for example:
eat 먹다 : 먹어버렸다 or 먹어 버렸다
have already eaten (The movement of "eat" had been finished) : 먹어버렸어요 or 먹어 버렸어요
come 오다 : 와버렸다 or 와 버렸다
have already come (The movement of "come" had been finished) : 와버렸어요 or 와 버렸어요
do a work 일하다 : 일해버렸다 or 일해 버렸다
have already done a work (The movement of "do a work" had benn finished) : 일해버렸어요 or 일해 버렸어요
"haven't + p.p. yet " as a auxiliary verb : V + 지 않았다
for example:
drink 마시다
haven't drunk yet 아직 마시지 않았어요.