Feb 2026 • 3 min read • punctuation & formatting • AI tells
How to Remove “AI Tells” on Mac: Long Dashes (—) and Smart Quotes
People don’t notice most “AI writing.”
They notice the punctuation.
Em dashes (—), spaced em dashes ( — ), curly quotes (“ ”), and curly apostrophes (’). These show up constantly in AI output — and they’re a dead giveaway in Slack messages, emails, docs, and internal updates.
This guide shows how to clean those tells up on macOS — fast — without reformatting everything.
It’s not about typography.
It’s about looking normal in everyday work writing.
Short answer
AI tools often output em dashes (—) and smart quotes (“ ” / ‘ ’).
Those characters are readable — but they stand out in everyday work writing.
The fix is to normalize punctuation: replace curly quotes with straight quotes and replace long dashes with consistent safe equivalents.
Key idea
Most “AI tells” in the workplace are pattern recognition — not software.
People have learned the visual signals: “smart punctuation,” overly polished phrasing, and a lot of em dashes. You don’t need to rewrite the message. You just need to normalize punctuation and formatting.
Common AI tells you can spot in one glance:
- Em dashes everywhere — like this — in casual messages
- Curly quotes: “like this” instead of "like this"
- Curly apostrophes: don’t instead of don't
- Overly even paragraph structure
This post focuses on the first two because they’re easy to fix and high signal.
What counts as a “long dash”
In practice, you’ll see these variants:
- Em dash: — (Unicode)
- Spaced em dash: space — space
- Double hyphen: --
None of these are “wrong.” But they’re not equally normal in everyday work writing.
Why em dashes are such a strong AI tell
Humans use em dashes sometimes. AI uses them constantly.
In email newsletters and published writing, em dashes look fine. In Slack updates and internal docs, they look suspiciously polished — or just “not how people type.”
If your goal is to sound natural in everyday workplace writing, you typically want:
- Shorter sentences
- Fewer parenthetical asides
- Hyphens, commas, or parentheses instead of em dashes
The cleanup rules (what to replace with what)
If you want to reduce AI tells, the goal is consistency and everyday keyboard punctuation.
Quotes and apostrophes
- “smart double quotes” → "
- ‘smart single quotes’ → '
- Curly apostrophe (’) in don’t → ' in don't
Dashes
- Replace — (spaced em dash) → - (or ( ) if it reads better)
- Replace — → - in casual work writing
- Replace -- → - (or remove entirely)
Brutal truth: in most workplace writing, using a simple hyphen with spaces is “normal.” Em dashes are not.
How to do it on Mac (practical options)
Pick one:
Option 1: Quick manual replace (fine if it’s rare)
If this happens once in a while, use find/replace in the destination app.
- Find: — Replace: -
- Find: “ Replace: "
- Find: ” Replace: "
- Find: ‘ Replace: '
- Find: ’ Replace: '
Downside: it’s repetitive, and you’ll miss stuff (especially ’ in contractions).
Option 2: Normalize before you paste (best if it’s daily)
If you paste AI text every day, you want an automatic cleanup step.
A macOS tool like Purifai can normalize punctuation and formatting before it hits Slack, Mail, Docs, or Word:
- “ / ” → "
- ‘ / ’ → '
- — / — / -- → - (or parentheses where it reads better)
It’s not about making your writing “fancy.” It’s about making it look normal.
A simple rule for workplace writing
If you wouldn’t type the character from your keyboard in a Slack message, it will stand out.
Normalize punctuation, keep structure, move on.
Most “AI tells” are fixable in seconds.
Punctuation is the easiest win.
The takeaway
Em dashes and smart quotes aren’t bad.
They’re just a signal — and people have learned the signal.
If you want your text to read normally in Slack and email, normalize punctuation before you paste.