Who is taller, the sister or the brother?
The sister is taller (than the brother).
Who is shorter, the sister or the brother?
The brother is shorter (than the sister).
Who is older, the grandfather or the grandson?
The grandfather is older (than the grandson).
Who is smaller, the boy or the girl?
The girl is smaller (than the boy).
Who is bigger, the boy or the girl?
The boy is bigger (than the girl).
Who is younger, the grandfather or the grandson?
The grandson is younger (than the grandfather).