Hyphens, en dashes and em dashes: the tiny marks causing a surprisingly big fuss
You may have noticed a small punctuation mark getting a lot of attention lately: the em dash. Some people now treat one as a sure sign that a piece of writing came from AI. It is not. It is just punctuation doing a job.
There are a few different dash-like characters, each with a slightly different use. Knowing the difference will not win you every pub quiz, but it can make web copy clearer and save a surprising amount of back-and-forth when someone says, “That looks AI-written.”
The hyphen: the joining-up mark
The hyphen (–) is the short one. It joins words that work together as a single description:
- user-friendly website
- small-business owner
- well-known local company
It is also useful for compound terms such as e-commerce and for avoiding ambiguity. A “re-signed contract” is not quite the same thing as a “resigned contract”. Tiny line, very different meeting.
The en dash: a neat way to show a range
The en dash (–) is a little longer. Its most common job is showing a range, including dates, times and prices:
- Monday–Friday
- 9am–5pm
- £500–£750
Think of it as meaning “to”. We would normally write “Monday to Friday” in an email, but the en dash is tidy in a heading, price guide or table.
The em dash: the dramatic pause
The em dash (—) is the longest of the three. It creates a pause, interruption or aside with a bit more energy than a comma:
Your website does not need to be complicated — it needs to help people find you and get in touch.
It is perfectly valid punctuation. Plenty of human writers have used it for centuries. That said, it can feel a little theatrical if every other sentence has one, and British business writing often reads more naturally with a full stop, comma or brackets instead.
So why do AI tools use em dashes so much?
AI writing tools learn patterns from enormous amounts of published text. The em dash turns up frequently in polished articles, explanatory writing and marketing copy because it is a handy way to connect two thoughts. When a tool is trying to sound fluent and confident, it can reach for that pattern more often than a person would.
That is a tendency, not a fingerprint. A human may use em dashes because they like them. An AI-generated draft may contain none at all. Punctuation on its own cannot tell you who wrote something.
What people usually notice is not the dash itself, but the overall feel: sentences that all have the same rhythm, a lot of sweeping claims, or wording that sounds polished without saying much. Good editing fixes that, whatever the first draft came from.
Our practical rule
Use the mark that makes the sentence easiest to read. Hyphens join, en dashes show ranges, and em dashes add a pause. If an em dash feels like it is showing off, replace it with a full stop and move on. No punctuation mark should have to carry the whole personality of a blog post.
In short: an em dash is not proof of AI. It is simply one more tool in the punctuation toolbox, alongside commas, brackets and the occasional very useful full stop.
