Use an em dash for a break or an aside in a sentence, an en dash for a compact range, and a hyphen to connect parts of certain words. A minus sign belongs to arithmetic. They can look similar at small sizes, but choosing by function is more reliable than choosing whichever line looks right.
Start with the job the mark needs to do. Are you interrupting a thought, connecting endpoints, or helping two words act together? That question usually resolves the choice before you need to consult a style guide.
Which mark does which job?
| Mark | Main job here | Teaching example | Quick check |
|---|---|---|---|
| Em dash: — | Interruption or aside | The launch is ready—except for the pricing page. | Is the second part a deliberate interruption? |
| En dash: – | Range | Review pages 14–19. | Can you read it as “to”? |
| Hyphen: – | Compound modifier | Send a two-page summary. | Do the connected words describe one noun? |
| Minus sign: − | Subtraction or negative value | 18 − 5 = 13 | Is this a mathematical operation or sign? |
The table covers common editing decisions, not every specialized publishing convention. Keep technical identifiers, product names and quoted material in their required form rather than replacing their punctuation just to make the page look consistent.
When does an em dash help?
An em dash gives an interruption noticeable emphasis. It can introduce a late qualification or set off an aside inside a sentence. Use that emphasis deliberately: several interruptions in one paragraph make the main point harder to follow.
Teaching example, final qualification: “We can send the proposal today—if finance approves the revised total.” The qualification arrives after a complete main statement. A quieter version would be “We can send the proposal today if finance approves the revised total.”
Teaching example, paired aside: “The revised schedule—approved by both teams—starts on Monday.” Remove the words inside the pair and read what remains: “The revised schedule starts on Monday.” The sentence still works, so the aside has clear boundaries.
That removal check catches a common editing error: opening an aside but forgetting to close it before the main sentence resumes. It also helps you decide whether the information is genuinely additional. If removing the aside makes the sentence misleading, consider putting that information into the main clause instead.
For a calmer tone, try parentheses around the aside. For two substantial statements, try a period. Read both versions aloud and choose the one that makes the action or decision easiest to find.
Should there be spaces around an em dash?
Follow the publication’s house style. Microsoft’s style guide uses no surrounding spaces. The University of Wisconsin–Madison editorial guide calls for a space on each side. These are different conventions, not competing definitions of the mark.
Teaching examples, spacing comparison: Microsoft style: “The draft—now approved—is ready.” Wisconsin style: “The draft — now approved — is ready.” Choose the required convention and apply it consistently within the document.
When should a range use an en dash?
An en dash commonly connects the endpoints of a compact range. In a meeting agenda, “items 3–7” means items 3 through 7. In a report, “2022–2025” gives the beginning and ending years. The Wisconsin en dash guidance illustrates this range use without surrounding spaces.
Plain words often read better in a sentence. Write “Review pages 14 to 19” if the symbol could be overlooked. With “from,” finish the construction with “to”: “The pilot runs from June to August.” With “between,” use “and”: “Choose a time between 9 and 11 a.m.”
House styles can take a different approach. Google’s developer documentation guide avoids en dashes and directs writers toward a hyphen or “to” where appropriate. For an unfamiliar audience, writing “to” makes the intended relationship explicit without requiring readers to distinguish two short marks.
When do words need a hyphen?
A hyphen can show that words work together before a noun. Compare “a three-day workshop” with “the workshop lasts three days.” In the first version, the number and unit jointly describe the workshop. In the second, they state its duration.
Another useful pair is “a well-organized handover” and “the handover is well organized.” Many temporary compound modifiers lose the hyphen after the noun, but established spellings can behave differently. Check your dictionary and house style instead of removing every hyphen automatically.
Do not add a hyphen merely because two describing words sit together. “A carefully prepared estimate” needs none between the adverb “carefully” and “prepared.” Microsoft’s hyphen guidance covers these modifier distinctions. For unfamiliar compounds, rewriting the phrase can be clearer than building a long chain of connected words.
What should you check before sending?
Treat the minus sign as a separate character. In a displayed calculation, use the true minus sign shown in the table, not an en dash chosen for its similar width. In software fields, follow the application’s required input format rather than replacing characters for appearance.
On a final pass, check each mark by purpose: remove paired asides temporarily, read ranges using “to,” and identify the noun a compound modifier describes. Then check spacing against the chosen house style. If you also use abbreviated clarifications, see the difference between i.e. and e.g. before sending.
For a desk reference, browse English punctuation and style guides on Amazon. Choose one that matches the kind of writing you do, and keep its conventions consistent across your documents.
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