This is the 13163rd most frequent Korean word.
두렵다는
"두렵다는" means "to be afraid" or "fearful."
Here, '두렵다는' is utilized in an embedded thought clause, describing the subject's emotional state regarding 'being left alone'.
혼자 남겨지는 것이 두렵다는 생각이 들었다.
I felt the thought that being left alone is frightening.
The word '두렵다는' is a form of the verb '두렵다', which means 'to feel fear'. In this sentence, it is used in a declarative clause to express the subject's feeling about 'a new place'.
그는 낯선 곳이 두렵다는 것을 인정했다.
He admitted that he is afraid of unfamiliar places.
In this instance of '두렵다는', it modifies '표정을' to describe the 'expression' as one associated with fear.