Collective nouns in english contents introduction

noun/verb: haircut, rainfall

Go to the salon and get a haircut before the photo shoot.

• 
  preposition/noun: underworld, bystander, onlooker
  

Many mythologies feature an underworld.

• 
  preposition/verb: output, outlook, overthrow
  

The CEO wanted to increase her factory's output of new products.

• 
  verb/noun: - swimming pool, breakwater, washing machine
  I can't wait to dive into that swimming pool.
  

• 
  verb/preposition: takeout, check-in, drawback
  

Let's order takeout for dinner.

Plural and Possessive Rules for Compound Nouns

There are no hard and fast rules concerning plurals of compound words, especially since some hyphens are omitted after time. In hyphenated words, usually the "s" goes at the end of the noun, as in daughters-in-law or mayors-elect. Sometimes it is at the end, as in go-betweens and higher-ups. In the open form, the "s" is often added to the noun, as in bills of fare, assistant secretaries of state, notaries public and full moons.
To make a compound word possessive, you usually add apostrophe + s to the end of the word, as in mother-in-law's car or five-year-old's birthday. If the compound word is plural, it can get a little strange with two "s" sounds close together, as in fathers-in-law's attire. If you can, it would be better to reword the sentence so the plural compound word does not need to be possessive: the attire of the fathers-in-law³.

Making Language Richer

Compound nouns are just one way in which the English language has become richer over time. Once you master compound nouns, you may wish to learn about compound adjectives and compound verbs to round out your understanding of compound words.
Words can be combined to form compound nouns. These are very common, and new combinations are invented almost daily. They normally have two parts. The first part tells us what kind of object or person it is, or what its purpose is. The second part identifies the object or person in question. Compound nouns often have a meaning that is different, or more specific, than the two separate words.
First part: type or purpose Second part: what or who Compound noun
police man policeman
boy friend boyfriend
water tank water tank
dining table dining-table
You have noticed that the compound noun can be written either as a single word, as a word with a hyphen, or as two words. There are no clear rules about this. A good rule of thumb is to write the most common compound nouns as one word, and the others as two words.
The elements in a compound noun are very diverse parts of speech.
Compound elements
Examples
noun + noun bedroom
water tank
motorcycle
printer cartridge
noun + verb rainfall
haircut
train-spotting
noun + adverb hanger-on
passer-by
verb + noun washing machine
driving licence
swimming pool
verb + adverb lookout
take-off
drawback
adverb + noun onlooker
bystander
adjective + verb dry-cleaning
public speaking
adjective + noun greenhouse
software
redhead
adverb + verb output
overthrow
upturn
input
Stress is important in pronunciation, as it distinguishes between a compound noun and an adjective with a noun. In compound nouns, the stress usually falls on the first syllable⁴.
A compound noun is a noun that is made with two or more words. A compound noun is usually [noun + noun] or [adjective + noun], but there are other combinations (see below). It is important to understand and recognize compound nouns. Each compound noun acts as a single unit and can be modified by adjectives and other nouns.