よん だん活用 かつようじゃなかったです
yonda nka tsuyōjanakattadesu

Noun
Desu Copula

The polite, past negative form of 四段活用

1. Wasn't a group 4 verb.; Wasn't conjugated as a group 4 verb.

Past/Perfective
Negative
Polite
Casual Register
Linguistics