알고 있었고

knew, and

→ 알다
phrase Rare #24,012
knew, and Connects a past clause meaning “knew” to what follows.
KO: 그는 길을 알고 있었고, 우리를 안내했다.
EN: He knew the way and guided us.

이제 직원들은 나를 알고 있었고, 내가 어느 날 올지도 알고 있었다.

By then, the staff knew who I was and knew I might show up any day.

난 모두를 알고 있었고 모두 날 알았다

I knew everyone, and everyone knew me.

— 좋은 친구들 (1990)