Used before nouns and noun phrases that denote a single but unspecified person or thing.
예문
1. A dog is faithful. (개는 충직하다) 2. a murder (살인 사건) 3. in a sense (어떤 의미로는) 4. Rome was not built in a day. (로마는 하루아침에 이루어지지 않았다) 5. She has such a wonderful voice. (그녀는 목소리가 썩 좋다)
