Phrasal adjectives (or adjectival compounds, or compound modifiers) are phrases that serve as adjectives, e.g. six-hour delay, one-way street, tried-and-tested solutions, up-to-date catalogue, come-as-you-are invitation, and grammar-intensive blog. Phrasal adjectives often need hyphens, not just for grammar but also for readability. Hyphens tighten and demarcate the phrases, which is especially helpful when multiple compounds are used:
fast-growing free-range poultry
two-and-a-half-hour on-campus tour
In these examples, each group of words acts as a single idea (fast-growing poultry, not fast and growing poultry). By clarifying each group with one or more hyphens, these strings of modifiers need no further disentangling. Note that hyphens are not used if the phrase follows the object. Rewriting earlier examples:
Our catalogue is up to date
These solutions are tried and tested (clichéd but correct)
If your text has too many hyphenated phrasal adjectives, a simple rearrangement along those lines can often clear things up.
Writers should be careful not to overuse hyphens. H. W. Fowler described them as “regrettable necessities, and to be done without when they reasonably may”. Regrettably, they are more commonly done without in unreasoned ways. When long strings of interconnected modifiers are written without hyphens, they put unnecessary work on the reader.
Neglecting even a single essential hyphen can lead a reader astray, as shown by the following example in Ernest Gowers’ The Complete Plain Words:
When Government financed projects in the development areas have been grouped…
Hyphen omissions can also be amusing: imagine a school of twenty-odd teachers, and beside it a school of twenty odd teachers. A well-placed hyphen reduces the potential for such ambiguity.
An example from the Oxford Manual of Style is a little used car. Interpreting this phrase fussily, a little used car is a small second-hand car, but most readers would infer that the car hasn’t been used much. This is a reasonable assumption, since little-used is quite a common phrasal adjective, and small is used more often than little to describe car size. But the punctuation and meaning don’t match up, so you should be aware that in some contexts a reader might object.
Because the rules and guidelines are not commonly understood, hyphens in phrasal adjectives tend to be ignored or haphazardly applied. Strictly speaking, only the last of the following formulations is correct:
non profit making organization
non-profit making organization
non profit-making organization
(As are non-profit organisation and not-for-profit organisation. See my post on non-life-threatening unselfconscious hyphens.) Of course, there are exceptions. Hyphens are omitted when the phrasal adjective begins with an adverb ending in -ly:
professionally typed letter
environmentally friendly products
Here, the -ly adverbs necessarily modify the adjectives that follow them, so a connecting hyphen is redundant and, to a sensitive eye, unsightly. Since this is the English language, there are also exceptions to the exceptions. Hyphens are reinstated if the -ly adverb is part of a longer compound:
Hyphens don’t enter the picture if the phrasal adjective consists of capitalised words or foreign phrases, unless the phrases are already hyphenated, in prefix form, or part of a longer compound:
National Gallery exhibition
Lough Derg scenery
ad hoc committee
cul-de-sac-based housing estates
I heard the last phrase on RTE News on 21 June 2008, and idly wondered whether (and how) the autocue had hyphenated it. In some styles, a single en dash is preferred to multiple hyphenation, especially when the compound is a proper noun: post–Lisbon Referendum mess.
A handy device is the suspended hyphen. Here, a hyphen is “hung” on the end — or, less frequently, the beginning — of part of a phrasal adjective, where there is an omitted element in a common series:
I get on well with my brothers- and sisters-in-law
Please direct sales- and service-related queries to…
A street of three- and four-storey buildings
Wilson Follett wrote: “Nothing gives away the incompetent amateur more quickly than the typescript that neglects this mark of punctuation or that employs it where it is not wanted.” The trouble is, it depends on who’s reading and judging, or even noticing.
Some authorities suggest hyphenating phrasal adjectives as context dictates, taking each instance as it comes and avoiding ambiguity wherever possible. Others advocate a general rule to preclude ambiguity altogether, but this can lead to excessive hyphen use. Much depends on your own style, audience and subject matter.