勉強 べんきょう熱心 ねっしんじゃありませんでした
benkyōne' shinja arimasendeshita

Desu Copula
na-Adjective

The polite, past negative form of 勉強熱心

1. Was not diligent.; Was not enthusiastic about studying.; Was not a keen learner.

Past/Perfective
Negative
Polite
Terminal Form