f one were to invent a language from scratch, it probably wouldn’t sound like English. After evolving for hundreds of years and borrowing many words and phrases from other languages, it’s an illogical mess. People learning English as a second language often raise sensible questions that native speakers seldom are able to answer: for instance, why does lose rhyme with dues instead of nose, as its spelling would suggest? Why does lead have two different pronunciations that mean different things?

Such anomalies and complexities are the reason stylebooks exist. A World Without Whom, the latest entry in this genre, is witty and entertaining. Emmy J. Favilla, Buzzfeed’s copy chief, does a particularly good job of describing the contributions that communications technology and social media have made to the language. She explains many of the terms and abbreviations that you have probably seen often without quite understanding: tfw is “that feel when”—as in, “tfw when you suddenly realize that you did not know what tfw means.”

Favilla tries to strike a balance between descriptivist and prescriptivist approaches to language. The first merely describes how people speak and write, without passing any judgments. The second lays down the law. Both sides have reasonable arguments. On the one hand, dogmatic prescriptivism can rule out many useful changes and additions to our mother tongue. If our language had been set in stone from the start, we would all sound like Beowulf. On the other hand, mere descriptivism provides no guardrails. As Favilla writes, “correct punctuation and proper grammar do play an incredibly important role in expressing both the elemental components and the complexities of human thought, of course.”

Favilla, however, leans in the descriptivist direction; the preceding sentence itself points to a problem with that approach. Many people have come to use incredible for “excellent” and incredibly for “extremely.” But the word incredible also means “unworthy of belief.” If you said that “the senator’s statement was incredible,” it would not be obvious whether you were calling it praiseworthy or dishonest. For the sentence in question, Favilla would have been better off with a word such as vitally, or better yet, no adverb at all.

When it comes to language, a bit of conservatism in order. Old usages are often worth keeping, while new ones may add murk instead of light.

Consider the key word in the book’s title. In ordinary spoken language, it can be acceptable to fudge the distinction between who and whom. It would sound weirdly stilted to say: “Whom are you gonna call? Ghostbusters!” In written English, however, the correct form is better. A book titled Who the Bell Tolls For would not make the earth move.

This distinction can also add clarity. A box on the Twitter home page says “Who to follow.” That phrase is ambiguous. It could mean: “These people are going to follow you.” Substituting the word whom would make it clearer that Twitter’s algorithms are identifying these folks as people whom you should follow.

Language is a battleground, and word choice often embodies contentious assumptions about philosophy and politics. Even today, some people still refer to the Civil War as “The War between the States,” suggesting a moral equivalence between the free North and the slaveholding South. When Favilla offers prescriptions, she often overlooks or downplays such controversies.

She recommends “person-first” when discussing disability, preferring “people with disabilities” to “disabled people.” As I learned while writing The Politics of Autism, people with a stake in this issue have fierce disagreements about the proper terms. (Autism politics is like faculty politics on crystal meth.)  Some regard their disability as a problem, while others see it as part of their identity. As one autistic advocate put it, referring to a “person with autism” is like referring to a man as a “person with maleness” or Catholic as a “person with Catholicism.” The answer to this dispute is not self-evident, and a book on language should not treat it as a settled matter.

Favilla disposes of the abortion issue with a single sentence: “Pro-choice and pro-life are loaded terms: use the neutral pro-abortion rights/abortion rights advocate or anti-abortion instead.” The issue is more complicated than she suggests, and her recommendation is far from “neutral.” People who would restrict the procedure usually avoid calling themselves “anti-abortion” because the prefix anti- tends to have negative connotations. Any term that includes the word rights in this context is also problematic because many people believe that the Supreme Court erred in Roe v. Wade and that the Constitution does not guarantee a right to abortion. With such a polarizing issue, it is hard to think of shorthand language that is not loaded. Perhaps we could write of “those who favor maintaining the current legal status of abortion” and “those who favor greater restrictions on abortion,” but such descriptions would scarcely fit into headlines or tweets.

Despite her admonitions, Favilla concludes with the words “Do what feels right to you.” This advice is not always helpful. When writing term papers, business memos, or cover letters, remember that your readers may be old-school types who keep Strunk and White’s Elements of Style on their desks. Usage may well be evolving in the ways that Favilla describes, but in the here and now, your fate could lie in the hands of people who care about the difference between who and whom.