Tā zhěngtiān wányóuxì, yèhuāngyúxī, chéngjì zìrán xiàhuá.
He plays games all day - his studies suffer from amusement, so his grades naturally slip.
Tips
history
From 韩愈's essay 《进学解》 (Tang dynasty): 业精于勤，荒于嬉；行成于思，毁于随 - 'a vocation is perfected through diligence and ruined through play; conduct is built through reflection and destroyed through following the crowd'. One of the most-quoted lines in classical Chinese on education.
usage
Almost always cited together with its other half 业精于勤 ('a vocation is perfected through diligence'). A standard exhortation in school speeches and parental lectures.
