Used to express worry, concern, or fear that something might happen. Combines the prospective question ending -(으)ㄹ까 with 보다 (to see/think). The pattern implies "thinking about whether something might happen" and worrying about it.

• •Worry: "비가 올까 봐 우산을 가져왔어요" (I brought an umbrella worried it might rain)
• •Fear: "늦을까 봐 일찍 출발했어요" (I left early for fear of being late)
• •Often followed by a precautionary action