This is the 802nd most frequent Korean word.
사이
The Korean word "사이" means "relationship," "gap," or "interval" in English.
사이 is used here to indicate the relationship or connection between two people.
형과 나 사이에는 믿음이 있다.
Between my brother and me, there is trust.
사이 indicates the spatial interval or distance between two objects.
책상과 벽 사이에 의자가 있다.
There is a chair between the desk and the wall.
사이 is used to denote the conceptual boundary or relationship between two ideas or states.