年齢 ねんれい相応 そうおうではありませんでした
nenrei sō ōdewa arimasendeshita

Noun
Desu Copula
no-Adjective

The polite, past negative form of 年齢相応

1. Was not age-appropriate.; Did not befit one's age.

Past/Perfective
Negative
Polite
Formal Register