무섭다 is one of those emotion words whose usage pattern changes with the subject's person. With third person subject, it means they are/look scary (유경은 무서워요 = 유경 is scary/menacing). With first person subject, it means the speaker is scared (나는 무서워요 = I am scared). The two are often combined: 나는 유경이 무서워요 = I am scared/afraid of 유경). The proper way to say "be scared" for the third person is 무서워하다, as in 유경은 개를 무서워해요 (유경 is afraid of dogs). We normally don't say 유경은 무서워요 to mean "유경 is scared", but there are some exceptions. For example, we say it if it's a quoted phrase, as in "유경은 무섭다고 해요" (this can be "유경 is said to be scared/scary" - context dependent). In fictional writing and dram narrations may say it like this because they often describe the characters' thoughts in a first person perspective. So the typical sentences to remember are: - 호랑이는 무서워요 = A tiger is scary. (3rd person, scary) - 나는 호랑이가 무서워요 = I am scared (of tigers). (1st person. Note 는, 가) - 제 동생은 호랑이를 무서워해요 = My brother is afraid of tigers. (3rd person, scared. Note 은, 를) There are many emotion words that work this way, like 슬프다/슬퍼하다, 기쁘다/기뻐하다, 부끄럽다/부끄러워하다, 아쉽다/아쉬워하다, 안타깝다/안타까워하다, and so on.