"Who is your mother?"
Translation:ʻO wai kou makuahine?
Can anybody please explain the grammatical difference between an initial ʻO and He? My vague sense is that when ʻO is used without any explicit verb, it establishes equality between two nouns (A is B, e.g. he is my father), while He is classification (A is a B, e.g. he is a policeman).