하나

In a sentence

• 나는 사과 하나를 먹었다.

  I ate one apple.

  Here '하나' is used as the numeral 'one', quantifying the noun '사과' (apple), emphasizing the quantity of items.

• 이 중에서 하나를 골라봐.

  Pick one among these.

  In this sentence, '하나' is used to indicate a choice of an individual item from a group, emphasizing the singular selection.

• 우리는 한 마음으로 하나이다.

  We are one in heart.

  Here, '하나' is used symbolically to convey the concept of unity or being 'one' as a whole.