Compound Adjectives in English: Formation, Hyphenation & Examples

A compound adjective is a modifier made up of two or more words that work together to describe a noun. When the compound adjective comes before the noun it modifies, the words are usually joined with a hyphen: a well-known author, a five-year-old child. When it comes after a linking verb, the hyphen is usually dropped: The author is well known. If you are unsure whether a compound adjective is hyphenated, the Oxford Learner's Dictionaries is a good place to check.

Compound adjectives are extremely common in English and appear in everyday speech, journalism, and formal writing alike. Learning the most frequent patterns allows you to recognise new ones immediately and to build your own without making errors.

Formation Patterns at a Glance

Structure	Example	Notes
Adjective + Noun + -ed	old-fashioned	The noun takes the -ed suffix. Very common with physical or style descriptions.
Number + Noun	five-year-old	The noun stays singular even when the number is more than one: a ten-minute walk.
Adverb + Past Participle	well-known	Common with well-, badly-, highly-. Hyphen before the noun; no hyphen after a linking verb.
Noun + Present Participle	time-consuming	The noun is the object or source of the action expressed by the participle.
Adjective + Past Participle	open-minded	Describes a quality of character or condition. Also: narrow-minded, short-sighted.
Noun + Adjective	world-famous	The noun indicates the scope or domain of the adjective: sugar-free, smoke-free.
Adverb + Present Participle	fast-moving	The adverb modifies the participle: hard-working, long-lasting.

Examples in Detail

“A well-known author”

Here well-known is an adverb + past participle compound. Well tells us how the author is known, and the two words together function as a single adjective. Before the noun: a well-known author (hyphen). After the verb: The author is well known (no hyphen). Other examples of the same pattern: badly-written, highly-regarded, newly-built.

“A part-time job”

Part-time is an adjective + noun compound that has become so fixed in English it is always hyphenated, even after a linking verb: She works part-time. It describes the nature of the employment. The opposite, full-time, follows the same pattern. These fixed compounds must simply be learned as vocabulary items.

“A last-minute decision”

Last-minute is a adjective + noun compound used attributively. It means something done or decided at the very end of the available time. Similar expressions include last-ditch (effort), last-resort (option), and eleventh-hour (agreement). All are hyphenated before a noun.

“A thought-provoking film”

Thought-provoking follows the noun + present participle pattern. The noun thought is what the film provokes, and the present participle provoking carries the verbal meaning. Other examples of this structure: time-consuming, heart-warming, eye-catching, breath-taking.

More Formation Examples by Pattern

• Adjective + Noun + -ed: old-fashioned, broad-minded, warm-hearted, cold-blooded
• Number + Noun: five-year-old, ten-minute (walk), three-bedroom (flat), two-hour (delay)
• Adverb + Past Participle: well-known, well-dressed, badly-damaged, highly-trained
• Noun + Present Participle: time-consuming, record-breaking, award-winning, ground-breaking

Common Mistakes

• Forgetting the hyphen before a noun.
  ✗ a well known author
  ✓ a well-known author
  Without the hyphen, the reader may briefly parse well and known as separate modifiers.
• Adding a hyphen after a linking verb.
  ✗ The author is well-known
  ✓ The author is well known
  When the compound follows be, seem, become, etc., drop the hyphen in most cases.
• Making the noun plural inside a number compound.
  ✗ a two-hours delay
  ✓ a two-hour delay
  The noun inside always stays singular when the compound modifies another noun.
• Treating fixed compounds as two separate words.
  ✗ a part time job / a last minute decision
  ✓ a part-time job / a last-minute decision
  Some compounds are so established that they are always hyphenated, regardless of position.

Practice Tips

• Learn patterns, not just words. Once you know that noun + present participle always works like time-consuming, you can build new ones: money-saving, risk-taking, attention-seeking.
• Check position. Each time you write a compound adjective, ask yourself: is it before the noun or after a linking verb? That determines the hyphen.
• Read widely. Newspapers and quality journalism use compound adjectives heavily. Note them as you read and add them to your vocabulary records.
• Practise with number compounds. Describe things around you: a two-storey building, a four-hour journey, a six-week course. Keep the noun singular.
• Use a dictionary to check fixed forms. Some compounds have become single words (easygoing) or are always hyphenated (well-being). When in doubt, check.

Practice Exercises

Explore related grammar topics:

All Grammar Topics Adjectives Adverbs Word Formation Punctuation

Frequently Asked Questions

What is a compound adjective?

A compound adjective is a modifier made up of two or more words that work together to describe a noun. The words are usually joined with a hyphen when the compound comes before the noun: a well-known author, a part-time job, a last-minute decision. When the compound follows a linking verb, the hyphen is usually omitted: The author is well known.

When do you use a hyphen in a compound adjective?

Use a hyphen when the compound adjective comes before the noun it modifies: a thought-provoking film, a five-year-old child. Omit the hyphen when the compound follows a linking verb such as be, seem or become: The film was thought provoking. Some fixed compounds, like part-time and well-being, keep the hyphen in all positions.

What are the most common compound adjective patterns?

The most common patterns are: adverb + past participle (well-known, badly-damaged); adjective + noun + -ed (old-fashioned, warm-hearted); noun + present participle (time-consuming, award-winning); number + noun (five-year-old, two-hour); and adjective + past participle (open-minded, narrow-minded).

Why is ‘a five-year-old child’ correct but ‘a five-years-old child’ wrong?

When a number-noun compound modifies another noun, the noun inside the compound must stay singular, even when the number is greater than one. The structure is: number + singular noun + (noun being modified). So we say a five-year-old child, a three-bedroom flat and a ten-minute walk — never five-years-old or three-bedrooms.

What is the difference between ‘well-known’ and ‘well known’?

Both forms are correct — the difference depends on position. Write well-known (with hyphen) when the compound comes before the noun: a well-known author. Write well known (without hyphen) when it follows a linking verb: The author is well known. This rule applies to most adverb + past participle compounds such as highly regarded and badly written.

Can compound adjectives come after the noun they describe?

Yes. When a compound adjective follows a linking verb (be, seem, become, appear), it is in predicative position and the hyphen is usually dropped: The decision was last minute. However, some fixed expressions keep their hyphen in all positions, and when in doubt it is safest to use a hyphen before a noun and omit it after a linking verb.

How do I form compound adjectives with ‘-ed’?

Add -ed to a noun that follows an adjective to create the pattern adjective + noun + -ed: old + fashion + -ed = old-fashioned; warm + heart + -ed = warm-hearted; cold + blood + -ed = cold-blooded. The -ed ending suggests that the person or thing has been “made” in the way described. This pattern is very productive in English and allows you to create new adjectives easily.

What does ‘thought-provoking’ mean and how is it formed?

Thought-provoking means causing people to think seriously about something. It follows the noun + present participle pattern: the noun thought is what the thing provokes, and provoking is the present participle. Other adjectives formed the same way include time-consuming (consuming time), eye-catching (catching the eye), heart-warming (warming the heart) and ground-breaking (breaking new ground).

What is the difference between compound adjectives and ordinary adjectives?

An ordinary adjective is a single word: famous, tired, old. A compound adjective is two or more words that work together as a single modifier: world-famous, dog-tired, old-fashioned. Compound adjectives often carry a more specific meaning than using two separate adjectives. For example, a well-dressed man is more concise than a man who is dressed well.

At what level should I learn compound adjectives?

Compound adjectives are typically introduced at B1–B2 on the CEFR scale (intermediate to upper-intermediate). At B1 you learn common fixed forms like part-time and well-known. At B2 you study the underlying patterns to create and understand new compounds. They are frequently tested in Cambridge B2 First and are important for IELTS Writing Task 1 and Task 2, where using varied vocabulary earns higher scores.