らぎょう変格 へんかく活用 かつようじゃないです
ragyōhenkakukatsuyōjanaidesu

Noun
Desu Copula
Negation Auxiliary

The polite negative form of ラ行変格活用

1. It's not a ru-verb.; It doesn't conjugate as a ru-verb.

Negative
Polite
Casual Register
Linguistics