おそふさんじゃなかったです
お祖父さんじゃなかったです
oso fusanjanakattadesu

Noun
Desu Copula

The polite, past negative form of おじいさん

1. Wasn't my grandfather.; Wasn't the grandfather.

Past/Perfective
Negative
Polite
Casual Register
Usually Written in Kana