Кто ? нужно his grandmother his father his sister his grandfather his mum пример: bill is a son for his mother

Bill is a grandson for his grandmother 
Bill is a son for his father 
Bill is a brother for his sister
Bill is a grandson for his grandfather 
Bill is a son for his mum 

1,4)grandson
2,5) son
3) brother
Используй конструкцию Bill is a ... и вставь нужное в зависимости от пункта.