Understanding Compound Adjectives

In English grammar, adjectives are used to describe nouns and give more information about them. A compound adjective is an adjective made by combining two or more words that work together to describe a noun.

What Are Compound Adjectives?

Compound adjectives are formed when two or more words are joined together to create a single adjective with a specific meaning. They are usually written with a hyphen (-) when they come before a noun.

Examples:

She is a well-known singer.
He bought a five-year-old car.
We stayed in a beautifully-designed hotel.

Compound Adjective Structure

Structure	Examples
Adjective + Noun + -ed	old-fashioned, middle-aged
Number + Noun + -ed	five-year-old, ten-minute-long
Adverb + Past Participle	well-known, highly-skilled
Noun + Adjective	world-famous, ice-cold

Common Compound Adjectives

Compound Adjective	Meaning	Example
well-known	famous	She is a well-known author.
hard-working	working with effort	He is a hard-working employee.
part-time	working fewer hours	She has a part-time job.
full-time	working regular hours	He is a full-time student.
high-quality	very good standard	This is a high-quality product.
user-friendly	easy to use	The app is user-friendly.

When Do We Use Hyphens?

Compound adjectives usually use a hyphen when they appear before a noun.

She bought a newly-built house.
It was a ten-minute walk.
He is a well-trained professional.

However, when the compound adjective comes after the noun, a hyphen is often not needed.

The house is newly built.
The professional is well trained.

Compound Adjectives With Numbers

When using numbers in compound adjectives, the number and noun are usually singular.

Incorrect	Correct
a five-years-old child	a five-year-old child
a ten-minutes walk	a ten-minute walk

Common Mistakes With Compound Adjectives

Incorrect	Correct
She is a well known actress.	She is a well-known actress.
He bought a two years old car.	He bought a two-year-old car.
This is a high quality service.	This is a high-quality service.

Exercises and Practice

Choose the correct compound adjective:

She is a _____ teacher. (well-known / well know)
They live in a _____ house. (two-story / two stories)
He is a _____ worker. (hard-working / hard work)
This website is very _____. (user-friendly / user friend)

Understanding compound adjectives helps learners create more natural and descriptive English sentences, especially in writing and professional communication.