Hyphens -

A hyphen is a dash that joins 2 words to form 1. It is the shortest and most common of the 3 dashes.

There are many different ‘rules’ around when or when not to use a hyphen in a compound, and quite a few exceptions to those rules. Go too far down this particular rabbit hole and you may well end up with a sore head.

We've captured some general principles in this entry. By applying them, you will be able to determine hyphen use in most cases. 

At the same time, our general recommendation is to minimise hyphens where you can, as long as your meaning is clear. If you're unsure in a particular case, look up the word in the Macquarie Dictionary.

Compound nouns

Hyphenate nouns structured as ‘verb + adverb’ or ‘noun + prepositional phrase’

go-ahead
mother-in-law
5-year-old

Traditional hyphenation principles for compound nouns can be quite complex and require a certain grasp of grammar. Our advice is to hyphenate nouns structured as:

  • a verb and an adverb
  • a noun and a prepositional phrase
  • 2 nouns of equal weight.
The committee's make-up is too heavily influenced by the mining sector.
Please submit your work to the editor-in-chief.
She is the property's owner-occupier.

You shouldn’t need a hyphen in the following compounds:

Compound nounExample
adverb + verb

  bypass

  input

verb + noun

  scarecrow

  swimming pool

noun + verb

  stocktake

  trainspotting

adjective + noun

  red tape

  hot dog

If you are not confident about your verbs and adverbs, the grammar content in the ASG will help you to brush up. The shortcut is to head for the Macquarie Dictionary and use the first option it offers. 

Compound adjectives

Hyphenate where the compound comes before a noun, unless there’s an ‘ly’ adverb involved

long-term goals
wholly owned subsidiary

Use hyphens in most compound adjectives where they come before a noun. This will keep the meaning clear that both words together qualify the noun. But if the adjective comes after the noun, you can remove the hyphen.

All team members need up-to-date software so they can work on the same files.

The team’s software must be up to date.

We generally don’t recommend using a hyphen if the compound includes a numeral, as long as the phrase cannot be misread.

A party must give 3 weeks notice in writing to end this agreement.
He ordered 3 metre-long planks. [3 planks that are each 1 metre long]
He ordered 3-metre-long planks. [An unknown quantity of planks that are 3 metres long]

If the compound includes an adverb ending in ‘ly’ before an adjective, you also don’t need a hyphen. The adverb form 'ly' already signals its relationship with the second qualifier.

If an adverb does not use 'ly', it is usually safer to add a hyphen unless there’s a third modifier in front of the adverb.

That is a highly irregular request.
A well-known entertainer was questioned by the police.
A very well known entertainer was questioned by the police.
Words with a prefix or suffix
Use a hyphen to separate awkward letter combinations or to clarify meaning
anti-inflammatory
re-enter
re-sign, resign

Many words with prefixes (such as ‘pre-’, ‘post-’, ‘inter-’ and ‘non-’) start out with a hyphen but gradually move to a closed-up form. Check the dictionary for recent usage tips.

The words to watch are the ones with 2 of the same vowel next to each other. These might need a hyphen to avoid being misread. But note that very common words like ‘cooperate’ and ‘coordinate’ have already lost their hyphens.

Let’s re-examine this situation at next month’s interdepartmental meeting.

The prefix ‘re-’ can also be tricky because there are several word pairs with this prefix that share the same spelling but have different meanings. If the ‘re-’ means ‘again’, you may well need a hyphen.

When I resigned, the company asked me to re-sign my non-disclosure agreement.
The council has re-created its design guidelines for recreation facilities as an online resource.

As for suffixes such as ‘-able’, ‘-ful’, ‘-ise’, ‘-ness’ and ‘-y’, you can usually just attach these directly to the base word without a hyphen.

But watch out for awkward letter combinations and suffixes relating to numbers, such as ‘-fold’, which we discuss below.

We are particularly grateful for her years of patronage, which have included a sizeable donation each quarter.
Shell-like structures need to accommodate localised vibrations.
Numerals with a prefix or suffix
Use a hyphen to link the numeral to the word
pre-2000
30-odd
10-fold

When you pair a numeral with a prefix or suffix, you should add a hyphen to make the link clear.

The conference organisers expect 300-odd people to attend.
Post-9/11, many countries strengthened their terrorism laws.

However, if you’re spelling out a number with the suffix ‘-fold’, you may not need a hyphen.

The problem this presents is twofold.
Spelt-out numbers
Use a hyphen when you spell out a number under 100 that has 2 words
forty-five
one hundred and sixty-three

We recommend using numerals in almost all cases, so you'll rarely need to spell out a number in words. The main places would be where:

  • a number starts a sentence and you can't easily rephrase
  • 2 numbers sit side by side and you need to distinguish between them for clarity.

To spell out a number below 100 that has 2 words, use a hyphen to connect them. And where these types of numbers form part of a larger number, keep the hyphen.

Sixty-seven people responded to our survey.
Three hundred and forty-two dogs were rehomed last year.
I was disciplined for taking twenty-two 15-minute tea breaks in 1 week.
See also:   Age,  Compound words,  Measurements,  Numbers,  Parts of speech,  Plurals