This is the 2225th most frequent Korean word.
집주인이
"집주인이" means "landlord" or "house owner" in English.
In this sentence, '집주인이' refers to the landlord, performing the action of returning home.
집주인이 저녁 늦게 집에 돌아왔습니다.
The landlord returned home late in the evening.
Here, '집주인이' is used to indicate the subject who is seeking a new tenant.
집주인이 새 세입자를 찾고 있습니다.
The landlord is looking for a new tenant.
In this case, '집주인이' is the one who sent the letter, making them the agent of the sending action.