missing hyphen in '100 yard house plan'

A missing hyphen in a compound modifier can change meaning or slow readers. When two or more words work together to describe a noun and appear before it, a hyphen usually signals they belong together.

Below: clear rules, short rewrite formulas, and many wrong→right pairs you can apply immediately.

Quick answer: when to hyphenate compound modifiers

Hyphenate compound adjectives that appear before the noun they modify (a well-known actor). Hyphenate number/age modifiers before nouns (a six-month plan, a 100-yard dash). Do not hyphenate compound adjectives after the noun (the actor is well known).

Before a noun: hyphenate (a two-week notice).
After a noun or with linking verbs: usually no hyphen (the notice was two weeks).
Numbers, ages, and fractions used as modifiers: hyphenate (a 10-year-old child, a one-third share).
Adverbs ending in -ly do not take hyphens with participles (a highly regarded scientist).

Core rule: compound modifiers before the noun

If two or more words jointly describe a noun and appear before it, hyphenate so the reader treats them as a single unit.

If the phrase follows the noun (usually after a linking verb), do not hyphenate.

Hyphenate: a full-time employee (before noun).
Don't hyphenate: She works full time (after verb).

Wrong: She is a well known artist.
Right: She is a well-known artist.
Wrong: He is a part time teacher.
Right: He is a part-time teacher.

Hyphenation rules you'll use most (numbers, ages, adverb+participle)

Numbers or spelled-out numerals used as modifiers before a noun are hyphenated: a ten-minute break, a 100-yard sprint. Age modifiers take hyphens when used adjectivally: a 10-year-old student.

Adverb + participle: hyphenate when the adverb is not an -ly adverb (well-known). If the adverb ends in -ly, do not hyphenate (a highly regarded scientist).

Numeric modifier: a six-month internship, a 100-yard sprint.
Age: a 10-year-old student (before noun).
Adverb + participle: a well-written review (hyphen), but a highly regarded review (no hyphen).

Wrong: We signed a 6 month contract.
Right: We signed a six-month contract.
School - Wrong: She is a 10 year old student.
School - Right: She is a 10-year-old student.
Wrong: That is a well known fact.
Right: That is a well-known fact.

Hyphen vs dash and spacing issues

A hyphen (-) links words in compounds. An en dash (-) shows ranges (2018-2020) or complex connections; an em dash (-) sets off clauses. Do not add spaces around hyphens inside compounds.

Avoid replacing hyphens with spaces or the wrong dash: both "100 - yard" and "100 - yard" are incorrect for a compound modifier.

Hyphen: tight, no spaces (full-time).
En dash: ranges (April-June) or complex compound connections in some styles.
Em dash: clause breaks - use according to your style guide.

Wrong: 100 - yard house plan
Right: 100-yard house plan
Wrong: state of the art design
Right: state-of-the-art design

Editorial note: tools and style

Grammar checkers catch many missing hyphens, but combine their suggestions with simple rules and context. For team consistency, pick one style guide and use automated checks to keep copy tight.

If a hyphen makes a phrase awkward, prefer a small rewrite to preserve clarity and tone.

Real usage for work and resumes (numbers and clarity)

In business writing, hyphens prevent ambiguity: a five-year strategy reads better than five year strategy. Pick numerals or words per your style guide and apply hyphenation consistently.

Resumes: six-month internship, three-year experience → hyphenate pre-nominal compounds.
Reports: a 12-point plan → hyphenate before a noun.
Consistency: choose one format and keep it across the document.

Work - Wrong: We organized a 6 month review meeting.
Work - Right: We organized a six-month review meeting.
Work - Wrong: Please submit a two week notice.
Work - Right: Please submit a two-week notice.
Work - Wrong: She drafted a 100 yard house plan.
Work - Right: She drafted a 100-yard house plan.

Try your own sentence

Test the whole sentence rather than the phrase alone. Context often makes the right choice obvious.

Many short wrong → right examples (work, school, casual)

Quick pairs you can paste into emails, essays, or posts. These show common places writers drop hyphens.

Work - Wrong: We launched a state of the art design.
Work - Right: We launched a state-of-the-art design.
Work - Wrong: The candidate has five years relevant experience.
Work - Right: The candidate has five years' relevant experience.
School - Wrong: The class is doing a year long project.
School - Right: The class is doing a year-long project.
School - Wrong: We followed a double blind study protocol.
School - Right: We followed a double-blind study protocol.
Casual - Wrong: I love that small town charm!
Casual - Right: I love that small-town charm!
Casual - Wrong: We had a fast paced weekend of hiking.
Casual - Right: We had a fast-paced weekend of hiking.

Rewrite help: quick formulas and three ready rewrites

Formula: identify the words before the noun that act together. If they jointly describe the noun and appear before it, hyphenate. Do not hyphenate when the first word is an -ly adverb; consider a rewrite if hyphens feel clumsy.

Shorthand: modifierA + modifierB + noun → modifierA-modifierB noun (when pre-nominal).
If confusing, move the modifiers after the noun or rewrite using of/for to clarify.

Rewrite:
Original: The company launched a 6 month campaign.
Rewrite: The company launched a six-month campaign.
Rewrite:
Original: He handed in a two page report.
Rewrite: He handed in a two-page report.
Rewrite:
Original: The small business owner meeting was canceled.
Rewrite: The small-business-owner meeting was canceled. Or: The meeting for small business owners was canceled.

Memory tricks and quick checks before you hit send

Two quick checks:

Move the modifier after the noun. If the sentence still reads naturally, a hyphen may not be required before the noun.
If the first word ends in -ly, do not hyphenate with the following word (a highly skilled player).

As a simple fallback in formal writing, hyphenate pre-nominal compounds for clarity and then adjust to your house style.

Wrong: She wrote a high quality paper.
Right: She wrote a high-quality paper.

Similar mistakes and grammar matters to watch

Watch possessives, plural forms of hyphenated compounds, and prefixes (preexisting vs pre-existing). Hyphens do not fix dangling modifiers-sometimes a rewrite is the correct solution.

If a compound could modify more than one noun, rewrite for clarity rather than forcing hyphenation.

Possessives: use five years' experience (possessive) or a five-year experience (adjectival) depending on context.
Plurals: two six-month plans (pluralize the main noun; the hyphenated modifier stays unchanged).
Prefixes: follow your style guide for forms like preexisting vs pre-existing.

Wrong: She attended the small business owner meeting.
Right: She attended the small-business-owner meeting.
Wrong: We need a 5 year plan's approval.
Right: We need approval for the five-year plan.

FAQ

Do I hyphenate compound adjectives after the noun?

Usually no. Hyphens are used for compound adjectives before the noun (a well-known author) and dropped when the adjective follows a linking verb (the author is well known).

Should I hyphenate numbers like 100-yard or write 100 yard?

Hyphenate numeric compounds used as modifiers before a noun (a 100-yard sprint). If the number follows the noun (The sprint was 100 yards), no hyphen is needed.

Is "high school student" hyphenated?

Most guides leave "high school student" open because "high school" is a stable noun. Use a hyphen in extended compounds: high-school-age children.

Do adverbs ending in -ly need hyphens?

No. Adverbs ending in -ly do not take hyphens with the words they modify: a highly regarded scientist is correct without a hyphen.

How can I quickly check a sentence for missing hyphens?

Move the modifier after the noun to see if it still reads naturally. Check whether the first word is an -ly adverb. For a fast mechanical check, paste the sentence into a grammar tool and then apply the short rules above.

Want quick feedback on one sentence?

Paste your sentence into a grammar checker to highlight likely missing hyphens and get immediate rewrite suggestions. Use the formulas here to choose between hyphenating or rewriting for clarity.