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Years ago, a student asked me to proofread her résumé. I found this sentence: “I am a highly-motivated and hard-working individual.” I circled every hyphen and wrote in the margin: “These should be hyphens, but only when they come BEFORE the noun. Here they come after ‘am,’ so no hyphens.” She was baffled. The hyphen rule is so counterintuitive that even careful writers get it backwards. Below, you’ll find the key rules: when to hyphenate compound words and when to leave them open, why numbers twenty-one through ninety-nine get hyphens, and the critical mistake that changes word meaning entirely (re-sign vs. resign). By the end, you’ll know exactly where that little dash belongs.
Key Takeaways
- The hyphen joins, it doesn’t separate — use it to connect two words that work together as a single idea (self-esteem, mother-in-law, well-known).
- Position matters — compound adjectives get hyphens only when they come BEFORE the noun. “a well-known author” (hyphenated) vs. “the author is well known” (no hyphen).
- Numbers twenty-one through ninety-nine always get hyphens — “thirty-five,” “sixty-two,” “ninety-nine.” But tens (20, 30, 40) do not.
- Don’t confuse hyphens and dashes — hyphens (-) join words; em dashes (—) show breaks in thought; en dashes (–) show ranges.
- Hyphenation clarifies meaning — “re-sign” (sign again) vs. “resign” (quit); “un-ionized” (not ionized) vs. “unionized” (belongs to a union).
What Is a Hyphen? Symbol and Name
The hyphen is a short horizontal line (-) used to join two or more words into a compound word or to separate syllables. It’s shorter than both the en dash (–) and the em dash (—). On most keyboards, the hyphen is the key next to the 0 (zero) on the top row of letters — just press it once with no spaces on either side.
The hyphen should not be confused with dashes , which are longer punctuation marks used differently. A hyphen joins; a dash separates or emphasizes. This distinction is critical for correct punctuation.
The Five Rules for When to Use Hyphens
Rule 1: Compound Adjectives (Before the Noun)
When two or more words join together to describe a noun, and they come before that noun, use a hyphen.
✓ Correct (before noun): She is a well-known author.
Explanation: “Well-known” comes before “author,” so it’s hyphenated.
✓ Correct (before noun): That is a high-quality product.
✓ Correct (after noun, no hyphen): The author is well known.
Explanation: When the same adjective comes AFTER the verb, the hyphen disappears.
✓ Correct (after noun, no hyphen): The product is high quality.
Example in context: The company sells state-of-the-art technology. (Three words joined before noun = hyphenate.) But: “The technology is state of the art.” (After noun = no hyphens.)
Important: Don’t hyphenate when one of the words is an adverb ending in -ly.
✓ Correct: a clearly written report (no hyphen, because “clearly” is an adverb)
✗ Incorrect: a clearly-written report
Rule 2: Numbers Twenty-One Through Ninety-Nine
Always hyphenate written-out numbers from twenty-one to ninety-nine. Never hyphenate multiples of ten (20, 30, 40, etc.) or numbers in the hundreds and above.
✓ Hyphenated: twenty-one, thirty-five, forty-two, sixty-seven, ninety-nine
✗ Not hyphenated: twenty, thirty, forty, one hundred, two thousand
Example in context: The committee has thirty-five members, divided into five groups of seven.
Age example: My grandfather is eighty-three years old. (When written as a compound adjective: “My eighty-three-year-old grandfather is visiting.”)
Rule 3: Compound Nouns (Some, Not All)
Some compound nouns are always hyphenated; others are written as one word or two separate words. When in doubt, check a dictionary.
Always hyphenated: mother-in-law, father-in-law, brother-in-law, sister-in-law
Always hyphenated: well-being, self-esteem, self-control, self-respect
Written as one word: notebook, classroom, textbook, firefighter
Written as two words: high school, coffee table, living room
Example in context: My mother-in-law and I enjoy spending time at the coffee table in the living room of our high school reunion.
Rule 4: Prefixes (Most Common Ones)
Some prefixes almost always take a hyphen; others rarely do. The most common hyphenated prefixes are self-, all-, and ex-.
Self- prefix (always hyphenated): self-esteem, self-control, self-aware, self-employed, self-portrait
All- prefix (always hyphenated): all-inclusive, all-encompassing, all-consuming, all-important
Ex- prefix (always hyphenated): ex-husband, ex-president, ex-employee, ex-coach
Non- prefix (usually no hyphen): nonprofit, nonfiction, nonsense
Exception: Use a hyphen when it prevents confusion or looks awkward. “Non-profit” and “nonprofit” are both acceptable, though the unhyphenated form is more modern.
Re- prefix (usually no hyphen): reorganize, reconsider, rebuild
But hyphenate to clarify meaning: re-sign (sign again) vs. resign (quit), re-cover (put a new cover on) vs. recover (get well)
Example in context: My ex-husband’s self-esteem improved after he became a self-employed consultant.
Rule 5: Line Breaks (Word Hyphenation)
When a word doesn’t fit at the end of a line in printed text, you can break it with a hyphen, but only at syllable boundaries. (This rule is less important in modern digital writing, where text wraps automatically, but it’s still correct in formal printed documents.)
✓ Correct syllable breaks: com-puter, in-ter-est-ing, hy-phen-a-tion
✗ Never split one-syllable words: Don’t break words like “thought” or “friend.”
✗ Never split words already hyphenated: If a word is “mother-in-law,” don’t break it as “mother-in-/law.”
The Hyphen vs. Dash Comparison
| Mark | Name | Length | Purpose | Example |
|---|---|---|---|---|
| – | Hyphen | Shortest | Joins words into one unit | well-known author |
| – | En dash | Medium | Shows ranges or relationships | 1990–2000; pages 45–50 |
| — | Em dash | Longest | Shows a break or emphasis | She was ready—or so she thought. |
Common Hyphenation Mistakes
✗ Mistake 1: Hyphenating when the adjective comes AFTER the noun.
✗ Wrong: She is a well-known and hard-working professional.
✓ Correct: She is a well-known, hardworking professional. (Or: “She is professional, well-known, and hardworking.”)
Why: When adjectives follow the verb or conjunction, they don’t need hyphens. “Hardworking” is now often written as one word when it stands alone; when paired before a noun, it’s “hard-working author.”
✗ Mistake 2: Not hyphenating compound adjectives before a noun.
✗ Wrong: She works in a high tech company.
✓ Correct: She works in a high-tech company.
✗ Mistake 3: Using a hyphen when a comma or dash would be clearer.
✗ Wrong: The report (which was 50-pages long) was thorough.
✓ Correct: The report (which was 50 pages long) was thorough. Or: The report—which was 50 pages long—was thorough.
✗ Mistake 4: Confusing re-sign with resign.
✗ Unclear: He decided to resign the contract next month.
✓ Clear: He decided to re-sign the contract next month. (Meaning: sign it again.)
✓ Different meaning: He decided to resign from the company. (Meaning: quit.)
Special Cases: When Hyphenation Clarifies Meaning
Some pairs of words change meaning dramatically depending on whether they’re hyphenated. Here are the most important ones:
| Unhyphenated | Hyphenated | Difference |
|---|---|---|
| resign | re-sign | “Resign” = quit; “re-sign” = sign again |
| recover | re-cover | “Recover” = get well; “re-cover” = put new cover on |
| unionized | un-ionized | “Unionized” = belongs to a union; “un-ionized” = not ionized |
| recreate | re-create | “Recreate” = have fun/play; “re-create” = create again |
Sample Dialogues
Between a manager and an employee
Manager: I want you to re-sign the agreement by Friday.
Employee: Do you mean sign it again, or quit?
Manager: Ah, I see the confusion! I wrote it wrong. I meant re-sign—sign it again. If I wanted you to quit, I’d write resign with no hyphen. That little hyphen makes all the difference.
Employee: Got it. That’s why hyphens matter!
Between a student and a writing tutor
Student: I wrote ‘a well-organized and time-saving method.’ But my teacher marked it wrong.
Tutor: Is this adjective sitting before the noun or after?
Student: Before. It’s ‘a well-organized and time-saving method.’
Tutor: Then it should be hyphenated — ‘a well-organized and time-saving method’ is correct. But if you’d written ‘The method is well-organized and time-saving,’ you wouldn’t use hyphens. Hyphens only apply when the adjectives come directly before the noun they describe.
Quick Quiz
- Which is correct?
A) She is a hardworking and dedicated employee.
B) She is a hard-working and dedicated employee.
C) Both A and B are acceptable, depending on the style guide. - Write out the number and add a hyphen if needed: 47
A) forty-seven
B) forty seven
C) forty-7 - Choose the correct sentence:
A) The team is all-inclusive in its approach.
B) The team is all inclusive in its approach.
C) The team approach is all-inclusive. - Fill in the blank with the correct word: “She will ________ the contract before the deadline.” (resign / re-sign)
A) resign (meaning quit)
B) re-sign (meaning sign again)
C) Either; they mean the same thing. - When do compound adjectives NOT need a hyphen?
A) When the adverb ends in -ly (clearly written, beautifully designed)
B) When the adjective comes after a linking verb (The report is well written.)
C) Both A and B
Answers: 1. C (Both are acceptable; British English prefers “hard-working”; American English often writes “hardworking” as one word) · 2. A (forty-seven) · 3. Both A and C are correct; B is wrong (all-inclusive must be hyphenated before the noun, but A is the better example showing it as an adjective) · 4. B (re-sign means to sign again; resign means to quit) · 5. C (Adverbs ending in -ly don’t need hyphens, and adjectives after verbs don’t need hyphens.)
Hyphenation in Different Contexts
Context 1: Academic writing
Example: The study used a well-designed, peer-reviewed methodology across thirty-two institutions.
Context 2: Business email
Example: Please review the high-priority, revenue-generating proposal by end-of-day tomorrow.
Context 3: Everyday writing
Example: I love my mother-in-law, but the last-minute changes drive me crazy.
Context 4: Technical or medical writing
Example: The non-invasive procedure was self-administered and well-tolerated by patients.
British vs. American Hyphenation
The rules above apply to both British and American English. However, there are minor stylistic differences:
- British English tends to use more hyphens with prefixes. For example: “co-ordinate” (British) vs. “coordinate” (American).
- American English tends toward fewer hyphens and more open compounds. “Email” is now standard in both, but British style historically preferred “e-mail.”
- Compound adjectives are hyphenated the same way in both: before the noun, yes; after the verb, no.
When writing for international audiences, choose one style guide (Chicago, AP, Oxford) and stick with it.
Related Articles
- ↑ Master Pillar: English Grammar
- Parentheses: When and How to Use Them Like a Native Speaker
- Apostrophe Rules: Possession, Contractions, and Common Mistakes
- ↑ Back to pillar: English Punctuation (Pillar)
Frequently Asked Questions
Is “hardworking” one word or “hard-working” with a hyphen?
It depends on where the word appears. Before a noun, use a hyphen: “a hard-working employee.” As a predicate adjective (after a verb), modern American English often writes it as one word: “The employee is hardworking.” British English more consistently uses the hyphen in both positions. Check your style guide for consistency.
Should I hyphenate compound numbers from one to twenty-one?
Only compound numbers from twenty-one to ninety-nine require hyphens. Numbers one through nineteen are written as single words (thirteen, fourteen, fifteen) with no hyphens. So: “twenty-one” (hyphenated) but “thirteen” (one word, no hyphen).
When do I use a hyphen with “non-“?
The “non-” prefix usually doesn’t require a hyphen: “nonfiction,” “nonprofit,” “nonsense.” However, use a hyphen if it prevents confusion (e.g., “non-member” could be ambiguous without it, and some writers prefer “non-profit” for clarity). Check a dictionary or style guide for specific words.
What’s the difference between a hyphen and a dash in URLs?
Website URLs use hyphens (no spaces): “www.example-site.com.” Hyphens in URLs don’t count as punctuation; they’re just characters separating words to improve readability for both humans and search engines.
Can I use a hyphen instead of a comma?
No. A hyphen joins words into a single unit; a comma separates items or clauses. Using a hyphen in place of a comma changes the meaning and breaks grammar rules. For example: “I bought apples-oranges-bananas” is wrong; “I bought apples, oranges, and bananas” is correct.
Do hyphenated last names like “Smith-Jones” count as one word or two?
A hyphenated last name is treated as one unit for alphabetization and grammatical purposes. For example: “Sarah Smith-Jones” would be alphabetized under “S” for Smith-Jones. It functions as a single surname, not two separate names.
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