What do you think is the best method to make the audience understand that you're writing with a limited vocabulary on purpose because your first-person narrator is an uneducated character? I want to write a story from the perspective of the chief of a nomadic nation (such as the Huns) who leads his people in battle. My idea is to use short sentences and repetitive vocabulary on purpose. Share any advice you might have in regards to this idea. Thank you.
Well, without seeing the writing itself, I'd say that's an excellent idea. As long as your character's speech patterns are markedly different from other characters who are different from him. Or are the same as other characters who come from the same place, with the same level of education. I would caution you not to go TOO deeply into reproducing exact grammatical mistakes. At least not to the point where the dialogue becomes difficult to read and comprehend. Just use a few of them to give the readers the idea. Short sentences will be excellent, if you're portraying this character as decisive. And repetition can also be characteristic of a person who brooks no nonsense, and expects to be obeyed without a lot of flowery flapdoodle. So these two tactics can serve several purposes at once. He's a battle leader, and he's not going to spend a lot of time talking?
I would be careful with this. Your character is not your writer, and a good writer can get the same thing across without dumbing down the language. Yes, what you're planning to do can work, but it would not be my approach. I also would struggle to read and stay interested in a book written this way. You don't want it to read like a book for children. You can get your point across in other ways so I would suggest thinking about that. This gives you a real chance to be creative. The easiest way isn't always the best. I've read things that were from a child's POV, but the language wasn't childish because it wasn't written for children. That's something to think about.
I think that you're assuming that a lack of written education means simple language use. I'm pretty sure that's not at all true. I seem to remember that at one time there was a debate about whether this newfangled writing thing would destroy the tradition of oratory and oral storytelling. Admittedly, I have no links (Well, I have this bit from Socrates, but it's not precisely on point.), but I think that your assumptions are incorrect here. Also, a link on "oral tradition" that is only somewhat on point: https://en.wikipedia.org/wiki/Oral_tradition I suspect that a leader would need to be fairly well-educated in his people's oral tradition, and have a certain amount of eloquence.
Personal opinion? To make that limited vocabulary very rich in symbolic, social and assosiative dimensions in a way which is clearer to people who live in empiria and harder to understand to people who live under paradigmatic limitations of understanding things. Try to imagine uneducated person with intelligence much, much higher than most university professors have. Try to imagine that this person is creative, master in tactical and strategic thinking and knows empiric world very well. If you use short sentences they must be short because that person is intelligent enough to say thing in a short way. If you think about using repetitive vocabulary, you might plan to make that person idiot - knowingly or not. Read Antifragile by Taleb. Think about Fat Tony character in that book. There you got something.