To talk about how we communicate is often to complain about it. There are too many emails, too many texts and too many social media posts. Some are hateful, others merely annoying; yet, to our dismay, we spend hours a day reading and writing them.

The linguist Gretchen McCulloch views this glut as a delightful abundance. “When I see the boundless creativity of internet language flowing past me online, I can’t help but want to understand how it works,” she writes in her book, “Because Internet: Understanding the New Rules of Language.”

“Why did emoji become so popular so quickly? What’s the deal with how people of different ages punctuate their emails and text messages so differently?” These are the types of questions she answers in her detailed but light-on-its-feet account of how we communicate now that we’re communicating online. (“We,” in this case, means internet-connected speakers of English, in particular its American varieties.)

For one thing, McCulloch argues, the internet is speeding up the evolution of English by increasing our ability to stay loosely in touch with, and mutually influence, one another. For another, linguists can now study the resulting changes more easily. The rapid increase in informal writing brought on by the internet has enabled researchers to take “a deeper look into day-to-day language than we’ve ever been able to see.” Older means of studying everyday expression involved time-consuming processes like conducting and transcribing interviews. And examples of informal writing used to come disproportionately from “the kinds of famous people whose papers get donated to archives.” Now – on social media and, with permission, in texts and emails – researchers can see informal language written by a huge (if still not perfectly representative) portion of the population. Linguists looking at geotagged tweets a few years ago found that “hella” was particularly frequent in Northern California and that the abbreviation “ikr” (“I know, right?”) was popular in Detroit.

We already knew that where we live and whom we spend time with influence how we speak. On the internet, McCulloch argues, it also matters when and why we got online in the first place. People who first used the internet to socialize, whether on AOL Instant Messenger or Snapchat, tend to adhere to linguistic norms that coalesced online. Those who use the internet rarely or for mostly practical reasons (work, shopping) often just use their offline communication styles online. That’s why some older people send texts with punctuation patterns, like repeated dashes or ellipses, that seem bizarre to younger recipients. They’re just “faithfully reproducing the conventions of a genre that they’re fluent in” – that is, informal writing in notes and postcards, where space was at a premium but complete sentences and standard punctuation were too formal. To prove her point, McCulloch cites several examples, including a jotted recipe (“Drop level tablespoons of dough on greased baking sheets … Bake in moderate oven”) and a postcard George Harrison once sent to Ringo Starr (“Lots of Love from Hawaii….”).

People who are more online-oriented tend to use line breaks rather than ellipses and dashes to separate informal thoughts. Breaks are more practical than they used to be, pixels being in greater supply than paper, and they improve readability. So “hey … how’s it going” has become

hey

how’s it going

The emergence of the line break as the most neutral informal pause marker is one tiny part of the typographical tone-of-voice system we’ve collectively developed. McCulloch’s excellent chapter on this system analyzes the many tools we use to convey tone of voice online, including ALL CAPS, worddd lengthennning, Ironic Capitals and many others: Lengthening “started as a very literal representation of longer sounds,” but people have begun to lengthen even silent letters (“sameee”), creating “a form of emotional expression that now has no possible spoken equivalent.” Centuries of writers tried to make irony punctuation happen (proposing ideas like backward-slanting italics and inverted exclamation points) before the internet brought us (tilde symbol)irony tildes(tilde symbol), which succeeded in part because they wryly play on (tilde symbol)(asterisk)(tilde symbol)(asterisk)(tilde symbol)sparkle enthusiasm(tilde symbol)(asterisk)(tilde symbol)(asterisk)(tilde symbol). Reading this chapter felt to me like hearing someone point out a personality trait I was only dimly aware of having. Oh. That’s why I do that.

If you spend your days “writing yourself into existence,” to use a lovely phrase McCulloch borrows from the technologist Jenny Sundén, even the most nuanced tone of voice is not enough. At least, this is how she explains the appeal of emoji. A kind of “digital embodiment,” emoji help us project emotion and intention we can’t convey with words alone. They are to informal writing what gestures are to informal speech. Like gestures, they can be divided into nameable “emblems” with culturally specific meanings (thumbs up, crossed fingers) and mere illustration or intensification of what we’re saying (a cake emoji added to a birthday message). A smiley, like an actual smile, can make “a demand into a softer request, or a seeming insult into softer teasing.”

As this (somewhat obvious) observation suggests, McCulloch – who writes the Resident Linguist column for “Wired” – is a great popularizer; she avoids the vagueness and condescension that sometimes mar writing about technical topics aimed at nonspecialists. Unsurprisingly, she has incredible control of her own range of expression. Her writing is upbeat and funny without (for the most part) feeling corny. Her neologisms are efficient: People who mark pauses differently are “dot-dot-dotters” and “linebreakers.” And her sentences are precisely evocative: “Words are just meat twitches until they determine whether you can get a job,” she explains. But what makes her enthusiasm so catching is her linguist’s conviction that all types of speaking (and texting and tweeting) are inherently valuable. “Language is humanity’s most spectacular open source project,” she writes. And even as we complain, we can’t help but contribute to it.

Megan Marz is a writer in Chicago.