The usage of a language is the manner in which the written and spoken language is used, the The Chicago Manual of Style says "the great mass of linguistic issues that writers and editors wrestle with don't really concern grammar at. When writing, it is very important to use language that fits your audience and matches purpose. Inappropriate language uses can damage your credibility. are speaking to or writing for (our audience). For example, we don't use the same language, nor do we speak in the same tone, when we talk to our friends as.