“Twin” is one of those wonderful hinge words in English, that mean two opposite things. Like the more celebrated “to cleave,” to twin means both to join and to divide, to double and to halve. As a noun, twin refers to one of a couple. As a verb it means to part, sever, sunder, deprive (of).

Cathleen Schine offers these definitions of “twin” as the epigraph for her enjoyable new novel, The Grammarians. Its plot charts the move from noun to verb. Laurel and Daphne are identical twins, born seventeen minutes apart. As the girls age, those minutes loom ever larger, symbolizing the differences they are surprised to discover open up between them. As small, very precocious children, the girls invent a private language. They listen to a record of My Fair Lady over and over, swanning about the house singing “Ah-wooo-dent it be loverly.” They are fascinated by words. The most significant event of their childhood is the day their father comes home with a lectern and a giant book he places on it in his study; they watch him wrestle it out of his trunk “like a doctor delivering a baby.” Their new sibling is the second edition of Webster’s New International Dictionary of the English Language; even as five-year-olds the oversize volume with its “cliff of compressed pages notched with steps the size of a fingerprint” becomes the centre of their world. Their mother contemplates forcing them to watch television to get them away from the damn dictionary for a while.

The girls become adults in the New York of the 80s, reviling Reagan but like plenty of comfortable white people not really suffering from him. Daphne makes a good living at a thinly disguised version of The Village Voice—perhaps this was possible in that lost world, though I’m not sure. Even more implausibly, she becomes famous as the author of a disapproving, sarcastic grammar column called “The People’s Pedant,” later turned into various books. Meantime, Laurel becomes first a kindergarten teacher, then a stay-at-home mother, and eventually a poet, assembling the often agrammatical expressions she finds in a collection of letters written by the relatives of soldiers to the Department of War—she “hear[s] their voices through the grammar”—into texts that are lauded by critics as generous but disparaged as appropriation by Daphne.

In other words, the sisters explore different ways of being women, of becoming creators, and, most importantly, of understanding language. Daphne is prescriptive, Laurel descriptive. Daphne believes that rules govern usage, Laurel that usage should shape rules.

Schine isn’t particularly subtle about her theme. At a deli, awaiting their blintzes, Daphne asks Laurel which is better, the way sour cream looks or tastes. Her sister calls it a tie:

Daphne thought about that as they ate, looking at the beautiful, shimmering sour cream, tasting it cool and smooth against the warm, buttery blintz. Could anything really be a tie? Was anything really equal to any other thing? She and Laurel were twins, eggs of a feather, so to speak, but were they tied? Tied together, yes. But tied?

The sentiment if expressed even more pithily early in the novel, ostensibly (but unconvincingly) from the POV of the young girls: “Identical twins, dressed in identical outfits—are they half or double?”

At the end of the blintz passage, Daphne turns from meditating on equality to thinking about words:

“‘Tie’ is a funny word,” she said.

“Sometimes,” Laurel said, “I think all words are funny.”

But funny ha ha or funny peculiar? Are words—and language more generally—something to marvel at, something that can be used in all sorts of peculiar ways, giving rise to new meanings, new uses? Or are they something that instills discipline and order? Is grammar truth or just the naturalized prejudices of rich people?

Most of us probably slide unreflectively from one position to the other. Sometimes sanguine about the seemingly infinite flexibility of language, especially English (think of all the ways we can use “fuck”). And sometimes grumpy about the decline of linguistic decorum, usually when it comes to uses that we for whatever reason hold dear (our particular crochets).

You’d think that how readers feel about language would be reflected in how they feel about the sisters. That is, prescriptivists will prefer Daphne while descriptivists will prefer Laurel. The problem, for me, is that Daphne is insufferably priggish, and it’s hard to imagine anyone liking her. (But I’m a pretty unreflective descriptivist, so I suppose I would say that.) Though, on reflection, Laurel is rather vague, so maybe what Schine has done is created characters that epitomize the stereotypical complaints about each philosophy.

The sisters eventually reach a version of détente (as the novel might put it, the ties that blind become, once again, the ties that bind), but not until after a years-long row in which they don’t speak. (The book is oddly structured, with a short opening chapter that references the feud, before sending us back to the beginning to find out how the twins got to that point, but then bursting past the opening frame, even ignoring it altogether, at the end.) In the end their love is reaffirmed—they remember that they are albumen and yolk and shell together.” But I found myself caring more for the novel’s minor characters than the grammarians themselves. Their cousin, Brian, turns in just a few deft scenes from bewildered child to snotty teen to sage adult. Their husbands, Michael and Larry, long-suffering and genial, are even more appealing, even though they really have bit parts. After the sisters break off relations, the men, whose initial forced friendship turns genuine, continue to meet in secret. In the end, I found their life-long affair more moving than the twins’ relationship with language.

In the end, how much you enjoy The Grammarians depends on how much you enjoy its almost aphoristic riffs on bits of language usage. Here’s Daphne, talking about her job:

Copyediting is helping the words survive the misconceptions of their authors.

And here’s Laurel, expressing a thought I’ve often had:

“I’m enervated,” she said after soothing and congratulating her sister. “I like that word because it sounds like it means the opposite of what it means.”

The Grammarians is a quick, fun read. Maybe more miss than hit, though. It’s definitely too schematic. And its evocation of 80s New York is glib, an exercise in nostalgia that makes it different from books actually written in that period. (There’s a brief reference to the AIDS patients Michael treats when almost no one else will, a discussion about how you can get avocados and radicchio at Fairway, the sort of period detailing that tv shows set in the past spend enormous amounts of time and money getting right and which the shows of the period effortlessly exude.) In this regard, The Grammarians made me want to return to the works of Laurie Colwin, another low-key Jewish writer specializing in relationship stories set in arty bourgeois New York. Colwin was both warmer and more bittersweet than Schine, a better writer altogether, and one whose reputation seems sadly to be at rather a low ebb just now. Schine’s novel is perfectly enjoyable, but I doubt I’ll remember it in a couple of months, whereas Colwin has stayed with me for decades.