eş: reale, vero, proprio, veramente, realmente, per davvero
köken: Univerbation of da + vero. The pronunciation with -vv- is due to the word's spelling being fossilized with the syntactic gemination of the traditional (Tuscan) pronunciation of da. The pronunciation with a single -v- reflects the regional and now standard pronunciation of da. Compare Spanish de veras, de a de veras (“for real”)
eş: naprawdę, doprawdy, zaprawdę, w rzeczy samej, w istocie
köken: Etymology tree Old Polish zaiste Polish zaiste Inherited from Old Polish zaiste. By surface analysis, univerbation of za + iste. Compare Czech zajisté, Serbo-Croatian zȁista /за̏иста.
köken: Etymology tree Bulgarian на (na) Bulgarian и́стина (ístina) univ. Bulgarian наистина Univerbation of на (na) + и́стина (ístina), literally, “in truth”.