Let’s talk about AI and the em dash —

There’s no need to stop using a perfectly good punctuation because you’re afraid to get called out for using AI. Just use it correctly.

AI tends to overuse em dashes. Usually a comma, period, or colon would be cleaner. Chatbots love that damn punctuation mark.

First, em dashes are extremely useful statistically because they’re forgiving. They can connect two related clauses, insert an aside, pivot tone, create emphasis, or rescue a sentence that might otherwise need restructuring. For a model predicting the next token, that makes the em dash a very safe piece of punctuation. It buys the sentence more runway.

Second, the training distribution matters. A lot of polished essays, journalism, marketing copy, blogs, and edited nonfiction use em dashes. Then instruction tuning tends to reward prose that sounds polished and fluid. So the model learns that an em dash often correlates with “good writer voice.”

Third, models have a habit of preserving continuity instead of ending thoughts cleanly. Humans are often more willing to write:

“That’s wrong. Here’s why.” A model is more likely to write:

“That’s wrong—and here’s why.” The em dash lets it keep one syntactic thread alive rather than committing to a full stop. That lines up with the broader bot tendency toward long, connected, explanatory sentences.

Fourth, there’s probably a feedback-loop effect now. AI-generated text has become part of the wider text ecosystem. If models overuse em dashes, and generated text gets published everywhere, future training corpora contain more of that pattern. That doesn’t mean “AI trained on AI ruined punctuation,” but it can reinforce stylistic habits.

And there’s one more piece I think matters a lot: the em dash is a perfect uncertainty punctuation mark. If the model isn’t fully committed to whether the next phrase is a new sentence, an aside, a contrast, or an elaboration, the dash works in all four cases. It is semantically flexible.

I use this in my writing style guide: “Use em dashes when a thought interrupts the flow of a sentence; otherwise, a comma, period, or colon will do.”

That style-guide instruction works because it removes that ambiguity. You’re essentially telling the model: “Do not use the dash as a general-purpose continuation device. Reserve it for interruption.” That forces it to choose the actual relationship between clauses instead of reaching for its Swiss Army knife.

Since adding that, I get correctly placed em dashes instead of em dashes everywhere.

So, if you use AI to write for you, embrace the em dash. Just remind the chatbot what’s right, because it already knows what’s stylistically wrong.

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