1 Is she Tom's younger sister? She is Tom's younger sister, isn't it? Who is Tom's younger sister? Whose sister is she? Is she Tom's younger or older sister?
2 Will it be very cold tomorrow? It will be very cold tomorrow, won't it? When will it be very cold? What will be the weather like tomorrow? Will it be very cold or hot tomorrow?
3 Did I see him yesterday? I saw him yesterday, didn't I? Who did I see yesterday? When did I see him? Did I see him yesterday or the day before yesterday?