しろはらとうぞくかもめじゃなかったです
白腹盗賊鴎じゃなかったです
shirohara tōzokukamomejanakattadesu

Noun
Desu Copula

The polite, past negative form of しろはらとうぞくかもめ

1. Was not a white-bellied thief gull.

Past/Perfective
Negative
Polite
Casual Register
Usually Written in Kana