1: most races all learn Kasual, which is the universal language of the universe, in addition to their native tongue. Races like elves or dragons disdains speaking Kasual, and will outright refuse to speak that language.
2. Any time isari would mention something he should not know and I, the author, did not disclose it beforehand, then assume it was given to him by Zenovia. Thoughout the novel she is constantly feeding him information. It would be extremely boring if I keep slowing the pace down to mention this detail.