やまのいもじゃなかったです
山の芋じゃなかったです
yamanoimojanakattadesu

Noun
Desu Copula

The polite, past negative form of やまのいも

1. It wasn't a yam.; It wasn't a mountain potato.

Past/Perfective
Negative
Polite
Casual Register
Usually Written in Kana