家か族ぞく の 中なか で 妹いもうと が 一いち番ばん 若わかい。kazoku no naka de imouto ga ichiban wakai.Among the family, my sister is the youngest.Breakdown of kazoku no naka de imouto ga ichiban wakai.のnopossessive case particleがgasubject particleでdelocation particle (for events and actions)中なかnakain, inside; middle