What are Compound Adjectives? Definition, Examples, Rules & More!

Short and quick answer: Compound adjectives are adjectives that are made up of two or more words, such as “hard-pressed,” “goal-driven,” or “bloodthirsty.”

Compound adjectives often have a hyphen in them. However, in many cases, the hyphen is omitted.

In the guide below, we’re going to cover all of the above (and more) in detail.

Introduction

In grammar, you’ve probably come across the term “compound words” or “compound nouns.” Whenever there is the word “compound,” remember that it means “combination of two or more.”

So, when we say “compound words,” we mean a combination of two or more words that act as one word. For instance, “will-o’-the-wisp” is a word that’s made up of four smaller ones. So, it’s a compound word.

Remember chemistry in school? What’s a compound in chemistry? A compound is a substance made up of two or more elements. That’s where the word comes from. Keep this in mind. You’ll be able to easily remember the meaning of “compound” whenever you face it in any grammatical concept.

Now, coming back to the topic at hand.

Just as there are compound words and compound nouns, there are also compound adjectives. We’re going to learn about them in this guide.

Definition of a Compound Adjective

Here is a definition of compound adjectives by GrammarGramps:

A compound adjective is an adjective that is made up of 2 or more words.

Examples of Compound Adjectives

Here are some examples of compound adjectives:

• Well-known (famous or widely recognized)
• Hardworking (working with a lot of effort)
• Open-minded (willing to consider new ideas)
• Short-tempered (easily becoming angry)
• Good-looking (attractive in appearance)
• High-speed (moving or operating very quickly)
• Everlasting (continuing indefinitely)
• English-speaking (able to speak English)
• Part-time (working or happening for only part of the usual time)
• Record-breaking (better or greater than any previous record)

How Are Compound Adjectives Constructed?

Compound adjectives can be constructed in a number of ways. They are typically formed by combining two parts of speech together, such as an adjective and a noun, a noun and a past participle, and so on. Below, we’ve listed the various combinations along with some examples:

1. Adjective + Noun (short-term, first-time, long-distance)
2. Adjective + Present Participle (fast-talking, Spanish-speaking, backward-facing)
3. Noun + Past Participle (whitewashed, sun-dried, homegrown)
4. Number + Noun (second-place, nineteenth-century, four-wheel)
5. Noun + Adjective (ice-cold, sky-blue, cruelty-free)
6. Noun + Present Participle (French-speaking, mouth-watering, self-effacing)
7. Adverb + Past Participle (tightly wound, overpopulated, undercooked)
8. Adjective + Past Participle (double-baked, deep-fried, warm-blooded)
9. Noun + Noun (seasick, meat eater, bulletproof)
10. Adjective + Infinitive (easy-to-use, ready-to-eat, hard-to-find)
11. Number + Noun + Adjective (five-year-old, ten-foot-tall, six-year-old)
12. Noun + Preposition + Noun (state-of-the-art, up-to-date, out-of-date)
13. Past Participle + Adverb/Particle (built-in, worn-out, broken-down)
14. Adverb + Adjective (highly-skilled, newly-available, newly-formed)

Hyphen Usage Rules with Compound Adjectives

Hyphens are often used in compound adjectives. However, there are many situations where they are not supposed to be used. Knowing when to use the hyphen and when to omit it can be tricky, but we’ll make it easy. Here is a breakdown of all the rules that you need to know:

1. Use a hyphen when a compound adjective comes before a noun

You have to use a hyphen when two or more words work together as a single adjective before a noun.

• a well-known author
• a high-speed train
• a five-year-old car
• a full-time employee

2. Do not use a hyphen when a compound adjective comes after the noun

Omit the hyphen when a compound adjective follows the noun it describes.

• The author is well known.
• The train is high speed.
• The employee works full time.
• The car is five years old.

Exception: There are some exceptions to this rule. For instance, when you use an established compound adjective, the hyphen has to be kept in.

• The technology is state-of-the-art.

3. Use a hyphen when a compound adjective has a number

When a number is used in a compound adjective before a noun, hyphenate the entire compound.

• a twenty-five-year-old building
• a two-hour meeting
• a three-month course
• a one-way ticket

4. Do not hyphenate a compound adjective that starts with a regular adverb

When a compound adjective begins with a regular adverb, particularly an adverb ending in -ly, do not use a hyphen.

• a highly skilled engineer
• a carefully designed system
• a newly developed product
• a poorly written report

Note: This rule applies to regular adverbs such as highly, carefully, and newly. Flat adverbs such as well, fast, and hard can form hyphenated compounds.

• a well-written article
• a fast-moving vehicle
• a hard-working employee

5. Hyphenate fractions used as adjectives

When a fraction functions as part of a compound adjective before a noun, hyphenate it. (A fraction means a part of something.)

• a two-thirds majority
• a three-quarter inch pipe
• a one-half share

6. Hyphenate compound adjectives with a number + unit

When a measurement functions as an adjective before a noun, hyphenate the number and unit. This rule is similar to what we said about numbers being present in compound adjectives.

• a 10-meter cable
• a 500-page book
• a 20-minute presentation
• a 6-foot table

Remember, in these cases, the unit remains singular.

• a 10-meter cable ✅
• a 10-meters cable ❌

7. Use a hyphen to prevent ambiguity

Sometimes, a hyphen is used simply to avoid ambiguity. For example, if there are three words in a row, and two of them form a compound adjective, it’s possible that the reader could interpret them as three separate words and completely misunderstand the meaning.

Here are some examples.

• man-eating shark
• small-business owner
• high-school student

What are Open and Closed Compound Adjectives?

1. Open compound adjectives contain two separate distinct words that are separated by a space. For example, highly adept.
2. Closed compound adjectives are two words that are merged into one, and they don’t have a space between them. For example, hardworking.

Fact: Open, closed, and hyphenated are the three types of compound adjectives.

Using Superlative and Comparative Forms in Compound Adjectives

Just as regular adjectives have superlative and comparative forms, so do compound adjectives.

Here are some rules that you should remember:

1. When the first element is a simple adjective that already has -er/-est forms, that element takes the change, and the rest stays put: short-lived becomes shorter-lived, then shortest-lived. Long-term becomes longer-term, longest-term. High-risk becomes higher-risk, highest-risk.
2. When the first element is well, good, or bad, something similar happens, but the inflection isn’t just tacked on; it swaps entirely: well-known becomes better-known, best-known. Good-looking becomes better-looking, best-looking. Bad-tempered becomes worse-tempered, worst-tempered.
3. When the compound is built from a participle or a longer descriptive phrase, you can’t inflect any single word inside it, so more and most go in front of the whole thing instead: time-consuming becomes more time-consuming, most time-consuming. Award-winning becomes more award-winning, most award-winning. Widely-used becomes more widely-used, most widely-used.
4. When the compound functions more like a fixed technical or descriptive term, the same more/most pattern applies even if it looks like it should inflect internally: user-friendly becomes more user-friendly, most user-friendly. Cost-effective becomes more cost-effective, most cost-effective.

Here is a useful test that you can try: try inflecting just the first word on its own. If that word alone sounds natural in comparative form (short, shorter; high, higher), the compound will usually take it too. If the first word sounds awkward alone (time, “timer”? that’s not even the same word), the whole compound needs more or most instead.

What to Do if You’re Still Confused About Compound Adjectives

Not to worry! If you’re still confused about compound adjectives, there’s nothing to worry about. The technical definitions and classifications, etc., can all get a tad confusing.

Instead, just do this. Read this guide again. This time, don’t think about learning anything. Just breeze through it. Think about having a really boring chat with a buddy.

When you read this guide that way, you will automatically start noticing the different compound adjectives that we’ve used. You know, I have been a hardworking writer coming up with this. My keen-eyed readers will surely find compound adjectives when they start looking for them.

When you start noticing them, you’ll instinctively start understanding how they work. Once you’re done reading this guide, even if your intention wasn’t to learn anything, you’ll still be very comfortable with the concept of compound adjectives.

List of 20 Common Compound Adjectives You Can Start Using When Writing/Speaking

Here is a list of 20 common compound adjectives that you can use.

1. Well-known (before noun): He’s a well-known author.
2. Long-term (after verb): Their strategy is long-term.
3. Old-fashioned (before noun): He has old-fashioned taste in food.
4. Part-time (after verb): He only works part-time these days.
5. Full-time (before noun): He landed a full-time role at the firm.
6. High quality (after verb): The materials they use are high quality.
7. Low-cost (before noun): They chose a low-cost supplier.
8. Fast-paced (after verb): The environment there is fast-paced.
9. User-friendly (before noun): It’s a user-friendly app.
10. Cost-effective (after verb): The new method is cost-effective.
11. Award-winning (before noun): The award-winning cookbook sold out in a week.
12. Time-consuming (after verb): The audit turned out to be time-consuming.
13. Good-natured (before noun): He’s a good-natured coworker.
14. Bad-tempered (after verb): The cat gets bad-tempered around strangers.
15. State-of-the-art (before noun): The lab installed state-of-the-art equipment.
16. Two-faced (before noun): Everyone saw through his two-faced act.
17. Open-minded (after verb): The panel stayed open-minded throughout.
18. Narrow-minded (before noun): His narrow-minded boss rejected the idea.
19. Well off (after verb): His grandparents were well off.
20. Up-to-date (before noun): They need an up-to-date record of expenses.

By the way, we also have a list of 100+ common adjectives (of the regular variety) that you can check out.

FAQs

Do compound adjectives always have a hyphen in them?

No, compound adjectives don’t always have a hyphen in them. The hyphen is added in certain situations and uses that we’ve described above.

Sometimes, they are open, which means the two words have no hyphen between them, but there is a space separating them. Sometimes, they are closed, which means there is neither a space nor a hyphen in between the two words.

What are the three types of compound adjectives?

The three types of compound adjectives are open compound adjectives, closed compound adjectives, and hyphenated compound adjectives.