May I also know if there are any circumstances like Columbus that shows how did one persuade a person or court to agree with them? Who is the court translator?
First of all, Columbus did speak Spanish, although his competence is somewhat questionable. From his own writings we can gather that his Spanish was heavily contaminated from a previous learning of Portuguese, which makes sense. Prior to moving to Castile in 1485, he had been living in Portugal for quite some years (1477 to 1485, more or less).
As for the other question, he did not just go to the royal Court with his demands, he was introduced to it through acquaintances, and then acquaintances' acquaintances. I wrote a reasonably detailed answer some months ago. Here I leave 2: one on how Columbus convinced the Monarchs, and another one on how he convinced the crew:
https://www.reddit.com/r/AskHistorians/comments/fhc5xs/how_did_christopher_columbus_convince_queen/