This is the 1253rd most frequent Korean word.
확인한
"Confirmed" or "checked."
Here, "확인한" serves as a past participle to describe the information that was verified or cross-checked, modifying "정보" (information).
확인한 정보가 정확했어.
The verified information was accurate.
In this context, "확인한" is used in a clause to describe the individual who performed the act of confirmation, modifying "사람" (person).
확인한 사람은 그 곳에 없었다.
The person who confirmed was not there.
In this sentence, "확인한" is used as the past determiner to indicate an action where the speaker completed checking something, modifying "문서" (document).