年齢 ねんれい相応 そうおうじゃありませんでした
nenrei sō ōja arimasendeshita

Noun
Desu Copula
no-Adjective

The polite, past negative form of 年齢相応

1. Wasn't age-appropriate.; Wasn't fitting for their age.; Wasn't mature enough.

Past/Perfective
Negative
Polite
Terminal Form