先頭 せんとう部隊 ぶたいじゃありませんでした
sentōbutaijārimasendeshita

Noun
Desu Copula

The polite, past negative form of 先頭部隊

1. Was not a leading unit.; Was not the vanguard.; Was not in the forefront.

Past/Perfective
Negative
Polite
Terminal Form