雨の日に傘がなくて困るしんちゃん

What does “言葉遣い” mean in Japanese?

言葉遣い (kotobazukai) literally means “word usage” — 言葉 (“words/language”) + 遣い (“use/handling,” from 遣う, a variant of 使う). It refers to how someone speaks — word choice, politeness level, tone — not just what they say. Japanese has an unusually wide range of registers, from blunt slang to formal keigo, so kotobazukai is a word parents, teachers, and workplaces reach for constantly to correct someone’s tone without necessarily objecting to the content.

In the clip, Shin-chan (from Crayon Shin-chan) imitates a rude “monster” character’s exaggerated insults, and his mother interrupts with “ちょっとしんちゃん言葉遣いが悪いわよ” (“Shin-chan, your language is bad”) — not correcting facts, just register. The related phrase 言葉遣いが悪い/丁寧 (“has bad/polite speech”) is a stock way to describe someone’s manner of speaking independent of what they’re actually saying.