275 – Grammar tip: hyphens

Many people, perhaps most, don’t know how to use hyphens with compound adjectives. It’s worth learning because use or non-use of hyphens can make a difference to how people interpret your meaning.

I remember learning about various rules of grammar in school, but I don’t think my teachers ever mentioned the use of hyphens with compound adjectives. I suspect my teachers weren’t the only ones leaving this out, because it’s so common to see writing where hyphens are needed but absent.

Perhaps it sounds like a nit-picky grammar-nerd sort of issue that people don’t really need to worry about, but in my view it is worth paying attention to. At the very least, good use of hyphens is a skill that can help make your text more readable. And in certain cases the omission of hyphens can change your meaning in serious ways.

Here are some examples where hyphens avoid ambiguity, misinterpretation, confusion or just nonsense.

A violent-weather conference is a conference about violent weather.
A violent weather conference is a conference about weather, and the conference is violent.

A small-state senator is a senator from a small state.
A small state senator is a state senator who is small.

Built-in cupboards are cupboards that are fixed into the house.
Built in cupboards describes something that was constructed within cupboards.

A first-aid post is a post that provides first aid.
A first aid post is an aid post that is, in some sense, ranked first.

What is going on? The hyphen is binding together the two words that precede the noun. When they are bound together, they apply jointly to the noun. First-aid is one thing. A small-state is one thing. These bound-together things are adjectives because they describe the following noun. (What type of senator is she? A small-state senator.) They are compound adjectives because they consist of two or more words.

grammarIf we leave the hyphen out, the two words are not bound together and the last word in the pair moves over and belongs to the noun instead. The first word in the pair remains an adjective, but it’s now on its own, describing the next two words. (What type of weather conference was it? A violent one.)

In most cases, omitting the hyphen(s) from a compound adjective doesn’t cause as much ambiguity as the above examples. However, it often does affect the reading process, as the reader has to spend at least a little bit of time working out from the context whether or not the first two words in the phrase are linked together or not. With hyphens in place, a reader can just whiz along without having to puzzle about how to interpret the words. I think it makes the process of reading more relaxing and enjoyable.

Here are some examples from academic research papers where there should have been hyphens but they were originally omitted:

diffuse-source pollution
water-use efficiency
water-quality benefits
information-collection activities
cause-and-effect relationships
land-use change
land-use policy
water-sensitive cities
policy-relevant questions
spur-of-the-moment decision
long-term planning
short-term effect
systems-level interactions
low-impact option
short-term solution
long-term projects

If you’re excited by this stuff, you might like to know about some ifs and buts related to the use of hyphens in this way.

A compound adjective occurring after the noun don’t require a hyphen.

I have a water-proof jacket (hyphen).
My jacket is water proof (no hyphen).

Sometimes a particular pair of words can be a compound adjective in one situation (requiring a hyphen) and a noun in another situation (requiring no hyphen).

This is a long-run trend (with hyphen).
This trend will continue in the long run (no hyphen).

Multiple adjectives don’t need hyphens, only compound adjectives. In “an articulate intelligent person”, articulate and intelligent are two separate adjectives, so they don’t need a hyphen.

If the first word in the compound adjective is an adverb (skilfully, happily, stupidly), don’t use a hyphen because it’s obviously linked to the next word.

A skilfully negotiated result.
A happily married man.
A stupidly designed policy.

Finally, note that hyphens are not the only way to indicate that a set of words is a compound adjective. Here are some alternatives that you might prefer in some situations.

Quotation marks: The politician flashed his “trust me” smile.
Title Case: I found the Perth City Council building. (Often used for titles.)
Italics: It was an ad hoc decision. (Often used for foreign phrases.)

In these cases, you don’t also need to include hyphens because it is obvious that the words in quotes, title case or italics belong together.


  • 28 October, 2014 - 12:23 am | link

    David, thanks, this point about hyphen usage is something that I am constantly pointing out to my hyphen-insensitive students (and colleagues)!

  • John Pannell
    28 October, 2014 - 8:42 am | link

    Pardon my cynicism. You may now need to write a tutorial on parts of speech.

  • 28 October, 2014 - 7:49 pm | link

    Nice one Dave (or is it nice-one?)
    Some editors take a minimalist approach to grammar so that compound adjectives become nouns. Is there a rule for omitting the hyphen to create a single word: e.g. dry-land to dryland; wet-land to wetland; ground-water to groundwater; dry-stone to drystone; chain-saw to chainsaw?

    • 10 November, 2014 - 5:18 pm | link

      I don’t think there is any particular rule. Common usage is the main factor.

  • David Godden
    29 October, 2014 - 3:46 pm | link

    A tiny comment, Dave. Does your “rule”: “Italics: It was an ad hoc decision. (Often used for foreign phrases.)” infer that if we don’t use italics we ought to hyphenate? e.g. “ad-hoc”, “ex-ante”, “ex-post”, “ad hominem” etc. I hope not!! Because, as you say, these are phrases not compound adjectives. I think it would have been preferable to have omitted this example.

    • 10 November, 2014 - 5:16 pm | link

      I agree, it would be ugly. And unnecessary, as it’s obvious that the words belong together.

  • Helena Clayton
    31 October, 2014 - 11:53 am | link

    Hi Dave,

    Thank you for this highly useful (note lack of hyphen) summary. It has helped to sort out some of my confusions. But now I’ve realised I’m rather confused about the use of hyphens with compound nouns. e.g. “decision makers” and “decision making processes”. A sequel perhaps?

    • 10 November, 2014 - 5:21 pm | link

      “Decision makers” doesn’t need a hyphen.
      In “decision-making process”, “decision-making” is a compound adjective and needs a hyphen.

  • Helena Clayton
    31 October, 2014 - 12:29 pm | link

    *compound verbs

  • Brett Robinson
    18 December, 2014 - 6:49 pm | link

    Hi David. More than a little affected by Asperger’s Syndrome (a syndrome from which Asperger didn’t suffer), I wish to point out the misuse of colons and semi-colons in your article. When one creates a list;
    one should precede it with a semicolon, and
    separate the items with commas.

    Colons belong where the general is separated from the specific: As I’m doing here. Whenever the second part is a complete sentence, you must treat it as a complete sentence: The usual rules of grammar apply, including capitalisation of the first letter.

    But – Txtng is ur new Nglsh, so it dznt rlly mattr. Duz it? cu l8r. roflmao

    • 20 December, 2014 - 7:44 pm | link

      Thanks Brett. We’ll have to agree to differ there. There are plenty of authorities on English who say that lists should be introduced by a colon (e.g. the Oxford Dictionary for one) and none that I’ve ever seen that recommended a semicolon for this purpose. There is more than one allowable use of colons.

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