だてでわありませんでした
伊達ではありませんでした
datedewārimasendeshita

Noun
Desu Copula
na-Adjective

The polite, past negative form of だて

1. It was not as one might think.; It wasn't superficial.; It wasn't for show.

Past/Perfective
Negative
Polite
Formal Register
Usually Written in Kana