悪習[akushuu] bad habit
悪習慣[akushuukan] bad habit
演習[enshuu] practice
演習問題[enshuumondai] practice problem
演奏練習[ensourenshuu] musical rehearsal

学習[gakushuu] study
学習者[gakushuusha] learner
学習塾[gakushuujuku] private night-school
学習用[gakushuuyou] tutorial
学習用ヘルプ[gakushuuyouherupu] tutorial help