sustanciase

first-person form-of imperfect singular subjunctive third-person

sustanciarの一人称/三人称単数接続法過去形

English Meaning

first/third-person singular imperfect subjunctive of sustanciar

Para empezar, es imprescindible que sustanciase cada afirmación con pruebas concluyentes.

まず、各主張が決定的な証拠で裏付けられることが不可欠です。

To begin with, it is imperative that each claim be substantiated with conclusive evidence.