(1) Regarding the occurrence of the modern word “is”, (a) the medieval “is” was often used as “da-ji (jisha)” in the late medieval period, and accordingly the final form “is” disappeared in the early modern period, but in the late modern period, “is” with a different background (combining the literal translation of Dutch zijn “aru” with the complement “de”) was used in translations of Dutch studies books by Nagasaki translators. (a) The medieval “de aru” (a direct translation of Dutch zijn combined with the complement “de”) was used by the Nagasaki translator to translate Dutch books, and this was the origin of the modern “de aru” (Masahide Yamamoto), and (b) In the early modern period, “de aru” was frequently used in lectures by Chinese scholars, oral translations by national scholars, sermons by monks, and other works, and in the Edo period “de aru” was used in the Edo period. In the early modern period, it was often used in lectures by Chinese scholars, colloquial translations by national scholars, and sermons by Buddhist monks, and continued to be used as a term by the educated class during the Edo period. The Japanese Dictionary of the Japanese Language, Selection Edition https://kotobank.jp/word/である-332613
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