さん人称 にんしょう単数 たんすうじゃなかったです
sanninshōtan sūja nakattadesu

Noun
Desu Copula

The polite, past negative form of 三人称単数

1. Was not he/she/it.; Wasn't he/she/it.

Past/Perfective
Negative
Polite
Casual Register
Linguistics