Sarah Kaplan is a reporter for the Washington Post’s Morning Mix.

Founding Grammars
How Early America’s War Over Words Shaped Today’s Language

By Rosemarie Ostler

St. Martin’s. 309 pp. $27.99

How you say something matters as much as what you say. At least that’s the opinion of many grammarians, who have been quibbling about Americans’ use of language for as long as there has been an American language to fight over. Rosemarie Ostler’s “Founding Grammars” chronicles these word wars in wonderful, wonkish detail.

Beginning with Noah Webster, who wrote a series of instructional grammar books specifically for Americans before publishing his eponymous dictionary, Ostler traces the history of language criticism from the 18th century onward. Her book explains nearly every usage quirk you ever questioned and many more you’ve never heard of, including how the U dropped from “colour,” why generations of students have spent their elementary school years diagramming sentences and why no one uses the word “shall” anymore.

‘Founding Grammars: How Early America's War Over Words Shaped Today's Language’ by Rosemarie Ostler (St. Martin's )

At the center of the history is a raging debate over prescriptive vs. descriptive linguistics: Should grammar guides tell people how to speak or reflect the way they already do? Webster was an early advocate of the latter philosophy, and it quickly becomes clear that Ostler has taken up his mantle.

As anyone who has accidentally split an infinitive on the Internet is aware, the intricacies of these grammar rules still invoke passion among linguistic hard-liners. But for those of us who aren’t driven to violence by a misplaced adverb, Ostler’s book is most interesting when it delves into the grammar debates’ political consequences. For example, who knew that adding “revolutionize” to the dictionary was a way of snubbing British English? Or that Abraham Lincoln’s opponents claimed he was unsuited for public office because he used slang in his speeches? For years, correct grammar served as a social litmus test — a way to determine someone’s respectability from just a few sentences of speech.

In many ways, it still does. Lest readers think that grammatical outrage is just a quaint 19th-century phenomenon, Ostler also devotes a chapter to modern linguistic warfare — fights over whether “ain’t” belongs in the dictionary and “hopefully” is hopelessly flawed.

Three centuries after Webster called for an “American” language, grammarians haven’t stopped arguing about what exactly that means. Whatever side of the debate they fall on, word lovers and copy snobs will enjoy Ostler’s story of how we got here.