研究 けんきゅう熱心 ねっしんじゃなかったです
kenkyū nesshinjanakattadesu

Desu Copula
na-Adjective

The polite, past negative form of 研究熱心

1. Wasn't enthusiastic about research.; Wasn't keen on research.; Wasn't diligent in research.

Past/Perfective
Negative
Polite
Casual Register