A common refrain from writers on Twitter is that writing is hard. Often, this insight is accompanied by the rueful observation that tweeting is easy. This is, of course, the difference between informal and formal expression, between language that serves as a loose and intuitive vehicle for thought and language into which one must wrestle one’s thought like a parent forcing his squirming kid into a car seat. We’ve long had both formal and informal modes of speech. The first pours from political orators; the second winds around friends at a bar. But, as the linguist Gretchen McCulloch reveals in “Because Internet: Understanding the New Rules of Language,” her effervescent study of how the digital world is transfiguring English, informal writing is relatively new. Most writing used to be regulated (or self-regulated); there were postcards and diary entries, but even those had standards. It’s only with the rise of the Internet that a truly casual, willfully ephemeral prose has ascended—and become central to daily life.

McCulloch begins with a taxonomy; different cohorts of users have different linguistic tells. “Pre Internet People” (think grandparents) tend to avoid acronyms like “ttyl”—mostly because they don’t know acronyms like “ttyl.” “Semi Internet People,” who logged on, in the late nineteen-nineties and early two-thousands, as adults, are more likely to type “LOL” than “lol”; they don’t view digital conversation as the place for tonal subtlety. “Full Internet People,” who grew up with AOL Instant Messenger and joined Facebook as young adults, are fluent in text-speak but perhaps less steeped in the grammar of newer platforms like Snapchat and WhatsApp. (McCulloch identifies a source of mutual misunderstanding between Full Internet People, who “infer emotional meaning” in symbols like the ellipsis, and Semi Internet People, who perceive such additions as straightforward bits of sentence structure.) Finally, there are “Post Internet People,” who joined Facebook after, rather than before, their parents. They’re the ones to watch: the digital avant-garde.

For McCulloch, the primary feat of the digital writer has been to enlist typography to convey tone of voice. We’ve used technology to “restore our bodies to writing”: to infuse language with extra-textual meaning, in the same way that we might wave our hands during a conversation. One general principle is that communication leans toward the efficient, so any extra markings (sarcastic tildes, for instance, or a period where a line break will do) telegraph that there’s more to the message than its literal import. That’s how the period, in text messaging, earned its passive-aggressive reputation, and why so many visual flourishes default to implying irony. Similarly, the expressive lengthening of words like “yayyyy” or “nooo” confers a friendly intimacy, and technical marks (like the forward slash that ends a command in a line of code) find new life as social in-jokes (“/rant”). Typography, McCulloch writes, does not simply conjure the author’s mood. It instructs the reader about the purpose of the statement by gesturing toward the spirit in which the statement was conceived.

McCulloch’s project is, at heart, a corrective: she wants to puncture the belief that the Internet de-civilizes discourse. She brandishes research that shows that we become more polite as we get better at typing. (As with online irony, online civility emerges from linguistic superfluity, the perception that an extra effort has been made, whether through hedges, honorifics, or more over-all words.) To those who fear that the Twitter era is eroding our eloquence, McCulloch replies that, in fact, “all our texting and tweeting is making us better at expressing ourselves in writing.” She cites a study of nearly a million Russian social-media users, which revealed that messages in 2008 were less complex than messages in 2016. Through GIFS, emojis, and the playful repurposing of standard punctuation, McCulloch insists, Internet natives are bringing an unprecedented delicacy and nuance to bear on their prose.

To back up this (strong) claim, the book proposes that the Internet’s informal English actually draws from a variety of registers, using tools old and new to create finely calibrated washes of meaning. Considering a real text from a teen-ager’s phone—“aaaaaaaaagh the show tonight shall rock some serious jam”—McCulloch highlights the archaic “shall” next to the casual “aaaaaaaaagh.” Such intermixing, she argues, makes Internet-ese “a distinct genre with its own goals. . . . to accomplish those goals successfully requires subtly tuned awareness of the full spectrum of the language.” This smart observation is also destabilizing: if digital English is “informal,” but imports “formal” locutions, one wonders what the categories are for in the first place. As the book notes, the quest to make writing more emotionally precise, more speech-like, is not Internet-specific; during the modernist movement, writers often broke rules of grammar and punctuation. The language of James Joyce or E. E. Cummings suggests an alluring parallel to Internet-ese, as do other twentieth-century innovations (free verse, stream of consciousness, profanity) that asked an unbuttoned style to represent human interiority. McCulloch grants that traditional writing has tilled these fields before, and she does not deny that relatively old-school techniques—vocabulary, syntax—can load sentences with the exquisite inflections of conversation. Her point, rather, is that this skill is becoming commonplace. “We no longer accept,” she writes, “that nuanced writing is the exclusive domain of professionals.”

We may be living through a democratization of refined writing—but what, exactly, distinguishes Internet-ese from other experimental prose? There are certain authors—Tao Lin, say—whose fiction feels of the Internet, even in hard copy. There are also recognizable, Web-based sensibilities: shouty wit (Lindy West), prolix familiarity (Choire Sicha), depressive dreaminess (Melissa Broder). McCulloch discusses a few “extremely online” literary effects, such as the poetic blankness of minimalist typography, which omits punctuation and sometimes inserts spaces between letters to evoke a l i e n a t i o n. But she doesn’t really anatomize Internet voice. (She’s not interested, for instance, in the “because [noun]” construction that gives the book its title.) This is probably wise; the inclusion of evanescent fads might only date the work. Still, I found myself longing for a theory that harmonized the ideas of informality, irony, variety, and emotion.

McCulloch’s own style is the endearingly nerdy presentation of an educator. Her enthusiasm works as a sweetener; she knows that students enjoy both corny jokes and groaning at corny jokes. (The practice of lengthening words for emphasis, she points out, predates the Internet by “maanyyy years.”) These chatty lines also reinforce the author’s authority. She’s inside the clubhouse, sipping Martinis with Philosoraptor and Doge. All language declares identity, and yet the performative aspect of McCulloch’s writing feels, itself, Internetty—deeply concerned with inclusion and exclusion. In fact, if there’s one quality that the book consistently links to digital expression, it’s a hyper-attunement to in-groups and out-groups, a tribal awareness. The book offers a chapter on the “atom of internet culture,” the meme, which seduces users with the promise “of belonging to a community of fellow insiders.” The cultivating of solidarity can be empowering, but it also casts a shadow. The meme format, McCulloch writes, with its ability to make “abhorrent beliefs look appealingly ironic,” thrived during Donald Trump’s candidacy.

A sense of doubleness, of trade-offs, is what is perhaps lacking from this celebration of Internet style. Yes, emotional precision is more accessible to the digital writer. (Evoking a mix of outrage and self-deprecation is easy when you have caps lock.) But sometimes discipline vivifies thought. Sometimes, to co-opt a modernist principle, difficulty is good. One wonders whether the eggplant emoji, a shorthand for lust, discourages less efficient, but more original, expression: Rachel Cusk’s formal restraint, or the smolder of an Alan Hollinghurst sentence. McCulloch would say it doesn’t. Maybe that’s true. Her book’s almost political thesis—the more voices, the better—rebukes both the élitism of traditional grammar snobs and the cliquishness of, say, Tumblr. It’s a vision of language as one way to make room for one another.