歴史 れきし てき仮名遣 かなずかいでしょう
rekishitekikana zukaideshō

Noun
Desu Copula

Expresses probability in a polite manner ("probably…") of 歴史的仮名遣い

1. Probably historical kana usage.; Likely historical kana usage.

Polite
Presumptive
Conjecture