I’m worried that/about, so…: 을까 봐

A/V + 을까 봐 is used to express concern about something. The sense of worry is often implied but can be made explicit with 걱정되다:

제가 비행기 표가 너무 비쌀까 봐
제가 비행기 표가 너무 비쌀까 봐 격정돼요.
I’m worried that the plane ticket will be too expensive…

시간이 충분히 없을까 봐
I’m worried that there won’t be enough time…

한국에서 이사할까 봐
I was worried about moving to Korea…

A/V + 을까 봐 can also be followed by a second clause that acts as a solution – ‘I’m worried that/about, so…’:

비가 올까 봐 우산을 가져왔어요.
I worried that it would rain so I brought my umbrella.

버스를 놓칠까 봐 일찍 집을 나갔어요.
I was worried that i would miss the bus, so I left home early.

파일들을 날려 버릴까 봐 다른 컴퓨터들에서 저장했어요.
I was worried about losing my files, so I saved them on different computers.