Hyphens are punctuation marks that create a link between parts of the same word, or between 2 or more words that go together as a compound.
The use of hyphens varies widely and is probably the least stable aspect of written English. Australian and British English are more inclined to use hyphens than American English. American English tends to ‘set solid’ the words of a compound (i.e. put them together, without a space), or leave them ‘open’ (put space between them).
This section covers:
Use of hyphens in compound words is covered in Compound words.
The rules for hyphenation are complex, and there are many exceptions to the rules. These few key tips will help you.
Use hyphens to avoid ambiguity
The main reason to use a hyphen is to ensure that your meaning is clear. Your guide to deciding whether to use a hyphen should be whether the phrase or word is clear without it:
Hot water bottle [could mean a water bottle that happens to be hot]
Hot-water bottle [means a specific item – a bottle for hot water]
Most successful students [could mean the majority of the students who have done well]
Most-successful students [means the students who performed the best]
Reading the sentence aloud can help you to decide – if you naturally tend to run 2 of the words together to make the meaning clear, you might need a hyphen (or the word might be set solid to form a new combined word).
Be consistent in use of hyphens
Whatever decisions you make about hyphens, make sure you record them in a stylesheet. This will help you to be consistent throughout your text, and will also help you to develop general rules to guide the decisions you make about new words and phrases.
Determine what type of word you are dealing with
Asking these questions and following the advice will answer most of your hyphenation questions. However, not every compound will follow these guidelines, so take a look at the relevant sections to explore further.
Are you dealing with:
- a prefix? Usually set solid, unless the word would be ambiguous or look wrong
multiverse undertaker re-leased [leased again, vs set free] anti-inflammatory [not antiinflammatory]
- a suffix? Usually set solid
- a compound that could be a noun or a verb? Follow the verb or noun rule – nouns are set solid or hyphenated, verbs are set open
- a modifier (i.e. adds information to another word in the sentence)? Follow the modifier rule – modifiers before the noun are set solid or hyphenated; modifiers after the noun are set open
- a common word or phrase? Do not use a hyphen; set solid or leave open. Compounds that are well established are more likely to have lost the hyphen, especially noun and verb compounds
website downfall equal opportunity primary school [nouns]
babysit daydreamed downplay [verbs]
Did you know? New words are often created by compounding (where 2 or more words are brought together to form a single word). The usual path for a new word is for 2 words (e.g. to and day) to become hyphenated (to-day) and then for the hyphen to be dropped (today).
Many of the single words we know today started life as 2 or more words. But the longer form now looks strange. For example:
- any thing
- clock work
- every one
- for ever
- good bye
- in stead
- none the less
- note book
- some body
- teen age
- to morrow
- waist coat
- what so ever.
Use a dictionary or other reference
If in doubt, check a dictionary or other reference work relevant to your particular topic. Dictionaries are particularly useful to see whether a word has become common enough to be set solid.