They'll be at home at 10 o'clock,won’t they ? Разделительный
Will they be at home at 10 o'clock? Общий
Who will be at home at 10 o'clock? Вопрос к подлежащему
When will they be at home? Специальный
Will they be at home or at school at 10 o'clock? Альтернативный
