was watching/lookingInformal past-progressive form of 보고 있다. The exact meaning depends on context: it can mean “was watching,” “was looking,” or “was taking care of” something, as in 볼일을 보고 있었어.
KO: 어제 저녁에 집에서 드라마를 보고 있었어.
EN: I was watching a TV series at home last night.