うすばふゆうでわありませんでした
薄羽蜉蝣ではありませんでした
usuba fuyūdewārimasendeshita

Noun
Desu Copula

The polite, past negative form of うすばかげろう

1. Was not a thin feather mayfly.; Was not a delicate, ephemeral being.

Past/Perfective
Negative
Polite
Formal Register
Usually Written in Kana