please be specific so I can reflect on that.

In chapter 4, when the MC talks to nami about what happened, the choice of words seem like something a news anchor would say. "Ship met it's cruel demise, merciless, iill ated vessel, I'm sorry for your immeasurable loss." These words are too stiff and neutral when someone uses them in a 1v1 conversation. Like I said, it sounds like something a news anchor would say when describing an event in 3rd person. When you talk to someone in 1st person, the words are usually more 'unprofessional' and more personal. In other words your choice of words in dialogues are more like something someone would use to describe an event in 3rd person as a spectator or neutral party, than what you would use in a normal conversation. People use simple language when conversing with someone else.

"We had an accident at sea. We were attacked by pirates. They killed everyone on board and sunk my ship. My mother was with us and she died along with them as well." These words sound more personal. Of course not in the way I've written, I don't have any experience in writing. But you get my point.

There's a fanfic by the name of HP arcane thief. The dialogues in that are well written and simple. Read a few chapters and you'll understand what I mean.