Compound Nouns
Compound nouns are words that consist of two or more words. Every part of them is part of the meaning of the nouns.
Separated Compound Nouns
- Compound nouns are more commonly written with two separate words.
real estate – He works in real estate.
post office – Did you go to the post office?
light year – A light year is a way to measure distance.
water tank – How many water tanks are there?
full moon – Look out your window to see the full moon tonight.
swimming pool – We have a swimming pool in our country house.
Hyphenated Compound Nouns
- Some compound nouns are hyphenated.
mother-in-law – Do you get on with your mother-in-law?
master-at-arms – Who is the master-at-arms of this ship?
commander-in-chief – He is the commander-in-chief.
single-mindedness – I can’t stand his single-mindedness.
- Hyphenated compound nouns typically function as adjectives.
six-pack – Buy a six-pack beer.
free-for-all – They want free-for-all income for the poor.
Separated or Hyphenated?
- Without a doubt, the easiest way to determine whether you need separated or hyphenated compound nouns is that we use separated compound nouns as nouns while hyphenated compound nouns usually function as adjective in sentences.
Open air vs open-air
We enjoy hanging out in the open air in summer.
The afternoon was so hot my friends and I decided to go to an open-air bar.
Air traffic vs air-traffic
Air traffic was so heavy last night.
The air-traffic control had a hard time managing the situation.
Compound Adjectives
- Compound adjectives are normally structured in three different ways. Many compound adjectives are hyphenated.
noun + adjective | noun + participle | adjective + participle
Noun + Adjective
- These compound adjectives are a combination of a noun and and an adjective.
camera-shy – I am camera-shy.
accident-prone – Be careful. This is an accident-prone area.
sugar-free – I prefer sugar-free coffee.
Noun + Participle
- These compound adjectives are a combination of a noun and and a participle.
computer-assisted – They are using computer-assisted instruction.
user-generated – These are user-generated contents.
custom-built – It is a custom-built car.
Adjective + Participle
- These compound adjectives are a combination of an adjective and and a participle.
brown-haired – My girlfriend is the brown-haired woman.
ill-tempered – Andy is a little ill-tempered.
fair-skinned – Ana is a fair-skinned girl.
- Compound adjectives formed by combining well + participle or a phrase should be hyphenated when the compound is before the noun.
He created some well-known artworks.
He just checked his up-to-date account.
- However, do not hyphenate when the compound is after the noun.
His artworks are also well known around the world.
His account is up to date.
- Compound adjectives that describe ages and lengths of time are also hyphenated.
I have a five-year old daughter.
They found some two-centuries old relics.