This is the 18633rd most frequent Korean word.
신고했고
"신고했고" means "reported" or "have reported."
The word '신고했고' here means 'reported and', indicating the subject completed reporting the incident and proceeded to another action.
그는 사건을 경찰에 신고했고 조사를 요청했다.
He reported the incident to the police and requested an investigation.
In this sentence, '신고했고' is used to express the action of reporting a lost item, followed by a subsequent event.
잃어버린 지갑을 신고했고 곧 찾을 수 있었다.
I reported the lost wallet, and soon it was found.
Here, '신고했고' signifies notifying authorities about a hazardous condition, connecting it to the action of evacuating individuals.