One language has entire separate vocabularies just for showing respect

Japanese keigo isn't just polite word choice — it includes distinct verb forms and vocabulary sets for respectful speech (about someone else), humble speech (about yourself) and plain politeness, layered on top of ordinary grammar. Choosing the wrong register isn't just rude, it can sound like a grammar mistake, since respect is built directly into the language's structure rather than added through tone alone.

— Wikipedia contributors, Honorific speech in Japanese — Keigo