그녀가

In a sentence

• 그녀가 웃으면 세상이 밝아져요.

  When she smiles, the world brightens up.

  Here, 그녀가 is the subject and refers to 'she', with the topic marker emphasizing her role in the action.

• 그녀가 이야기를 시작했을 때 모든 사람들이 경청했어요.

  When she started speaking, everyone listened attentively.

  In this case, 그녀가 again acts as the subject, emphasizing the person initiating the action.

• 그녀가 무엇을 찾고 있는지 물어봤어요.

  I asked what she was looking for.

  Here, 그녀가 is used to indicate the specific subject (her) of the subordinate clause.