に就て[nitsuite] concerning
に就き[nitsuki] because of
去就[kyoshuu] committing one's self
就いては[tsuiteha] in line with this
就きましては[tsukimashiteha] in line with this

就く[tsuku] to ascend (the throne)
就ける[tsukeru] to install (a king, emperor, etc.)
就学[shuugaku] entering school
就学義務[shuugakugimu] compulsory school attendance
就学児童[shuugakujidou] school child

演奏練習[ensourenshuu] musical rehearsal
教練[kyouren] drill
訓練[kunren] practice
軍事教練[gunjikyouren] military training
軍事訓練[gunjikunren] military exercise

試練[shiren] test
手練手管[terentekuda] wiles
修練者[shuurensha] (Catholic) neophyte
熟練[jukuren] skill
洗練[senren] polish