Every speaker is a student of language, even if it is not our intent. But this is a book for the general student of linguistics. I can't believe I am saying "general" because I've never seen anyone go more into specifics than John McWhorter. He makes a general study of a whole juxtaposition of a variety of languages for the writer who is fascinated by the anthropology of linguistic development. Bear in mind, this book it is rather heavy, and overwhelmingly leaded with obscure trivia. If you are not frightened off by the idea of subconjugations in Ket, and the (illustrations of) grammar and impossibility of figuring out five tenses of Navaho—Verbing may weird English but who knows what it does to Navaho—If you're not scared off, maybe you're potentially an anthropological linguist and this book will be your friend.
From the beginning, McWhorter rhapsodizes about the peculiarities and idiosyncrasies of Archi, and click languages, and the strange grammatical constructions of obscure tongues almost no one speaks and one would think would be impossible to master. He submerges the reader in characteristics of languages so that we can hardly keep up with all the strange detail. But right at the point when this barrage of detail seems absolutely pointless, he talks about his five signal characteristics of language, (Ingrown, Dissheveled [sic], Intricate, Oral, Mixed). He illustrates with specific detail how languages evolve, how their complexities develop or decline. He also makes a point that when languages are spoken by a few people over time, they become more complex, but when spoken by larger groups for longer time, they get (or stay) dumbed down when influxes of new speakers learn simpler versions of the language. When languages are learned by adults they are dumbed down generationally—as opposed to the small, isolated communities that develop complex languages which can only be learned by children with their aptitude of language. He ranges in topic from the development of classifiers in Chinese and Cantonese, to the number of words for snow in Eskimo, to fetishes in Kikuyu that make it unlearnable to non-native speakers. He examines how an island language lost prefixes and suffixes when foreign adult speakers arrived and imperfectly learned and passed on the language. As an unwritten language, the old version would not, as McWhorter says it, have it's foot in the door. Such developmental hiccups allow the historian a foothold in muddling through the history of language.
Oh if this review seems clotted and lumpy, that is pretty much how I feel after reading What Language Is. There is so much detail that the content feels obscure and sluggish, even if an ambitious attempt is made to present the transformation and growth and development of language as both holistic and in a constant evolution. I did find it heavily academic, plus the electronic version I had was so badly formatted in places that I had difficulty figuring out if that was a misplaced footnote or some text was missing or extra. That may have been because I read on a kindle, or because it was an arc. Here and there were a smattering of illustrative stories and some sense of John McWhorter's charm, but the design suffers from academic overload and unclear organization. McWhorter is probably a humdinger in the classroom, but this tome suffers from a sense of massive density where it should be sharp and pointed. Not a must read in any sense, but of interest to linguists, especially in this age of dwindling care about language. At the risk of labeling myself a rube and a philistine, I must admit reading the last pages with respect for the depth and breadth of McWhorter's linguistic knowledge and a promise to myself to read the rest of his work after it has been edited. (This was an early arc.)