The AI Hyphen: A Tiny Tell That’s Reshaping How We Read and Write

This past summer, I became fixated on a single punctuation mark. Not a semicolon. Not an Oxford comma. Not a tilde.

A hyphen.

More specifically, the AI Hyphen.

It’s longer. It’s tighter. It clings to the words on either side without space. And once you start noticing it, you can’t unsee it.

I’ve spotted it in emails from colleagues, in blog posts from thought leaders, even in public statements from companies I admire. I look back at my past published pieces – and yes, I see it there, too. However, I’ve realized something: this isn’t just a formatting quirk. It’s a clue.

The AI Hyphen has become a fingerprint—a subtle signal that a large language model was involved in the writing. (Did you see what we just did there?)

A New Kind of Watermark

I use AI. I am using it more, and more transparently. I’ve created a badge to show when I’ve collaborated with it. I’m not perfect but am trying to model responsible, ethical use.

But, I also write all on my own. And when I do, I want my writing to feel like mine.

So when I started noticing the AI hyphen – tight, space-less, sometimes vanishing entirely when copied and pasted – I felt a shift. Not just in formatting. In trust.

Suddenly, a single punctuation mark had the power to cast doubt on the authenticity of a message.

The Hyphen Identity Crisis

I’ve used hyphens for years. Mine come with space before and after. They’re part of my rhythm. My voice. But now, I find myself deleting them. Not because I’ve stopped using AI. But because I don’t want my writing to look like AI wrote it when it didn’t.

I’ve seen this play out in professional settings. In personal notes. In public statements. The AI hyphen has become a kind of watermark, one that writers didn’t ask for and readers didn’t agree to interpret.

And here’s the kicker: I don’t even know how to create that unique hyphen myself! It just… appears. Like a formatting ghost.

Well, that was until I did some Googling…..

A Dash of History: The Em Dash Before AI (Courtesy of my CoPilot)

While we’re talking punctuation, let’s give a nod to the em dash—the longer, bolder sibling of the hyphen. It’s been around for centuries, quietly doing the work of interruption, emphasis, and dramatic pause.

Technically, an em dash is about the width of the letter “M” (hence the name). You can create one by typing two hyphens in a row (–) and letting your word processor convert it automatically, or by using a keyboard shortcut like Shift + Option + Hyphen on a Mac or Alt + 0151 on Windows (whatever that means).

Before large language models came on the scene, em dashes were mostly the domain of stylists and novelists. They showed up in literary fiction, in long-form essays, in the occasional blog post. But they weren’t everywhere. And they certainly weren’t a giveaway.

No one scanned a paragraph and said, “Ah, an em dash—clearly machine-generated.”

Now? It’s different.

LLMs love em dashes. They use them to connect ideas, to pivot mid-sentence, to add rhythm. And because they’re so consistent in their use, the em dash has joined the hyphen as a kind of tell—a formatting fingerprint that hints at AI involvement.

Did anyone care about em dashes before? Not really. They were punctuation wallpaper. But now, they’re part of the conversation. Part of the signal. Part of the subtle shift in how we read and how we trust.

What Are We Losing?

This isn’t just about punctuation. It’s about perception. It’s about the subtle ways technology reshapes our language, our credibility, and our sense of ownership.

Have we lost the right to use hyphens?

Have we reached a point where a single mark can undermine the perceived authenticity of our work?

Are we editing ourselves not for clarity or style… but to avoid suspicion?

The Summer of the Hyphen

This past summer, I saw it everywhere. In newsletters. In LinkedIn posts. In heartfelt messages from people I know and trust. And I started wondering: what does this tiny tell mean for us as writers?

Sometimes, I feel a tug when I see someone I care about posting something that carries the unmistakable trace of AI. Do I say something? Do I share my hyphen-awareness? Or do I let it pass by me like a leaf on the river, trusting that they’ll figure out their relationship with AI in their own time?

It’s a quiet dilemma. One that sits between curiosity and compassion. Between noticing and nudging. Between wanting to protect someone’s voice and respecting their journey.