お父(とう)さんsomebody else's father
お母(かあ)さんsomebody else's mother
お兄(にい)さんsomebody else's older brother
お姉(ねえ)さんsomebody else's older sister
妹(いもうと)さんsomebody else's younger sister
弟(おとうと)さんsomebody else's younger brother
叔父(おじ)さんsomebody else's uncle
叔母(おば)さんsomebody else's aunt
お祖父(じい)さんsomebody else's grandfather
お祖母(ばあ)さんsomebody else's grandmother