Compounds and Hyphenation

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In legislative drafting, as in other types of writing, we are often confronted with the problem of compound words and phrases-and where to use hyphenation effectively in order to make meaning clear. Despite the wide diversity in modern English usage in respect of hyphens (including disagreement among language specialists), there is, according to Fowler, "one principle that seems to command at least lip service from authorities. This is that the hyphen is not an ornament but an aid to being understood, and should be employed only when it is needed for that purpose." With this in mind, the Legislative Services Branch has formulated some general guidelines with respect to hyphenation and current accepted usage. Although personal preference may often diverge from generally accepted usage, the main objective of these guidelines is to assist in improving the readability of legislation.

Hyphenation may aid in establishing the grammatical and semantic relationships among words in compounds. We all recognize that an "old furniture-dealer" and an "old-furniture dealer" are not the same thing - thus strengthening the argument that hyphenation does effectively contribute to meaning. However, we sometimes experience difficulty in deciding how best to express the inter-connectedness of compounds - especially when dealing with sometimes complex compound modifiers. Proper use of hyphenation, when and where required, can help clarify meaning.

While numerous types of compounds exist, this note will concentrate on only two of them: compound nouns and compound modifiers. These two types seem to be the most problematic (and recurrent) in terms of drafting legislation. The note also looks at the capitalization of hyphenated compounds and includes a table of examples. First, a look at the basic notion of compounds.

Basic compounds

Several types of compounds exist:

  • open form, such as "middle class";
  • hyphenated form, such as "subject-matter" (our usage, following the OED); and
  • closed form, such as "childlike".

In English, many compounds - over time - go through all three types, transforming from open to hyphenated to closed form (for example, "fire fly", "fire-fly", "firefly"). The hyphen is often introduced as a visual link, so as to make the distinction that is made in speech by stressing the first word of the compound. A good dictionary, such as the Gage Canadian Dictionary, is your best source for determining the "current" status of such compounds (including those based on prefixes and suffixes).

Compound nouns - a few guidelines

  • 1.1 Hyphenate two nouns in apposition that indicate different but equally important functions (for example, "tractor-trailer", "city-state"). The compound constitutes a new, single idea.

  • 1.2 Hyphenate nouns normally written as two words, when they are preceded by a modifier which might create an ambiguity ("letter writers" but "public letter-writers" - the latter expression clarifying that the letter writers write for the public, rather than that they write letters that are of a public nature).

    Also, when a modifier applies to the first component of a compound noun usually written as one word, the compound noun must be separated into its component parts and joined to the modifier with a hyphen ("ironworker" but "structural-iron worker").

  • 1.3 Hyphenate compound units of measurement created by combining single units that stand in a mathematical relationship to each other (for example, "person-day", "kilowatt-hour").

  • 1.4 Noun-plus-gerund compounds are not hyphenated, except when used adjectivally (more on this later - see Compound Modifiers, item 2.8). They may appear as separate or single words (for example, "decision making", "problem solving", "shipbuilding"). (Note, however, that Canadian legislation contains several examples of hyphenated "decision-making" even when not used adjectivally. This is not recommended usage.)

Compound modifiers

Compound modifiers are often hyphenated to avoid confusion, such as the "old-furniture dealer" mentioned above. This is especially the case when compound modifiers precede the noun they modify ( for example, "an oil-based mixture"). When they follow the noun, there may be less need to use hyphenation to indicate meaning, but such hyphenation removes any ambiguity.

Most of our problems with knowing when and where to correctly hyphenate compound modifiers arise when such modifiers are themselves compounded with others.

Here are a few guidelines on compound modifiers and hyphenation.

  • 2.1 Unlike adjectives, adverbs (particularly those ending in "ly") are not usually hyphenated when compounded with other modifiers (for example, "publicly held securities"). The function of an adverb is to qualify the word next to it, so there is little chance of misunderstanding. However, when an adverb might be mistaken for an adjective, a hyphen will distinguish between the two (for example, "extra-judicial duties" rather than "extra judicial duties").

  • 2.2 Hyphenate noun-plus-adjective compounds - when they occur in that order - whether used attributively (before the noun) or predicatively (after the noun) (for example, "duty-free goods", "goods that are duty-free").

    Similarly, noun-plus-participle compounds are also hyphenated (for example, "time-consuming activity", "an activity that is time-consuming").

  • 2.3 Comparative and superlative forms of adjectives are hyphenated when compounded with other modifiers (for example, "shorter-term loan").

  • 2.4 Hyphenate compound adjectives in which one element is a cardinal or ordinal number (whether a figure or a word) and the other a noun (for example, "six-month period", "12-person capacity"). The introduction of the "open" style into the 1985 Statute Revision (for example, six month period) has been superseded.

  • 2.5 To avoid ambiguity, adjective-plus-noun and participle-plus-noun compounds, when modifying another noun, are usually hyphenated (for example, "crude-oil exporting countries", "large-scale development").

    Even if this type of compound follows the noun it modifies - as long as it remains adjectival - it is hyphenated (for example, "a development that is large-scale").

  • 2.6 Adjective-plus-participle compounds, whether used before or after the noun, are hyphenated (for example, "an odd-sounding name", "a name that is odd-sounding").

  • 2.7 Adjectives joined with a noun having the "ed" ending are always hyphenated (for example, "able-bodied").

  • 2.8 Two-word compound adjectives made of a noun and a gerund - when they precede the noun they modify - are hyphenated (for example, "decision-making process").

  • 2.9 Compound adjectives whose final component is an adverb of direction or place (in, out, down, up, etc.) - when they precede the noun - are also hyphenated (for example, "drive-by shooting").

  • 2.10 Preposition-plus-noun compound adjectives are hyphenated as well (for example, "after-tax income").

  • 2.11 However, chemical terms used as adjectives are not hyphenated (for example, "calcium nitrate deposit").

  • 2.12 "Suspended" compounds, in which an element common to successive compound adjectives is omitted, are hyphenated (for example, "interest- or revenue-producing scheme", "two-, four- and six-metre widths").

  • 2.13 Adjectival phrases are often hyphenated to avoid confusion with nouns. For example, "the common law" is a noun phrase, while "common-law partner" is an adjectival phrase. Hyphenation also promotes clearer understanding when two (or more) compound adjectives modify one noun (for example, "common-law mirror-image rule").

A lack of hyphens in such adjectival phrases can cause readers to stumble and struggle for meaning. A phrase such as "the benefit of insurance and waiver of subrogration clauses" should be hyphenated to read "the benefit-of-insurance and waiver-of-subrogration clauses".

Common sense should dictate when adjectival phrases need to be reined in and the sentence or phrase reworked. The hyphenation in "a waiver-of-all-rights-to-subrogration clause" does not facilitate understanding - the legislative counsel would be better advised to opt for "a clause waiving all rights to subrogation".

According to Fowler, compound modifiers are often a case of all or nothing when it comes to hyphenation. Neither hyphen can be dispensed with in such phrases as "three-quarter-hour intervals" or "submarine-cable-laying ships". However, by introducing a preposition and rephrasing, the hyphens may be done away with entirely (for example, "intervals of three quarters of an hour").

Note that the adjectival phrases mentioned in this subitem precede the noun they modify. The presence of an adverb or preposition in such phrases is often a signal to hypenate (for example, "cost-of-living index", "coming-into-force date", "on-the-job training", "subject-by-subject analysis").

Capitalizing hyphenated compounds

When capitalizing hyphenated compounds, one rule of thumb is to always capitalize the first element and to capitalize the second element if it is a noun or proper adjective or if it has equal force with the first (for example, "Risk-Taker", "Non-Christian", "City-State").

In general, do not capitalize prefixes and suffixes added to proper nouns (for example, "American-made"). Also, do not capitalize the second element if it is a participle modifying the first element or if both elements constitute a single word (for example, "English-speaking People", "Self-sustaining Reaction", "E-flat Minor").


Despite the vagaries and seeming contradictions of various sourcebooks and rules, hyphenation, when used with common sense, can help clarify the meaning of compounds. Visualize the absurdity represented by the non-hyphenated phrase "a fair skinned English gentleman". By signalling the structural relationships among the component parts of compounds, hyphenation assists the reader in navigating the text. The examples set out above are only a beginning, but they do show the precision that may be achieved through a discriminating use of the hyphen.





noun plus noun, equal function (see 1.1)


one-word compound noun, first component of which is modified (see 1.2)

structural-iron worker

two word compound noun, possibly ambiguous modifier (see 1.2)

public letter-writers

units of measurement (mathematical relationship) (see 1.3)


noun plus participle (see 2.2)

time-consuming activity

noun plus adjective (in that order) (see 2.2)

duty-free goods

noun plus gerund, adjectival (when before noun) (see 2.8)

the decision-making process was flawed

comparative/superlative plus other modifier (see 2.3)

shorter-term loan

adjectives with cardinal/ordinal number (see 2.4)

six-month period

adjective plus participle (see 2.6)

odd-sounding name

adjective plus noun with "ed" ending (see 2.7)

able-bodied person

adjective with an adverb of direction or place (when before noun) (see 2.9)

drive-by shooting

suspended compounds (see 2.12)

interest- or revenue-producing scheme

preposition plus noun, when adjectival (see 2.10)

after-tax income

Usually hyphenate:



adjective plus noun, when modifying another noun (see 2.5)

large-scale development

participle plus noun, when modifying another noun (see 2.5)

crude-oil exporting countries

Do not hyphenate:



noun plus gerund, non-adjectival (see 1.4)

the Board's decision making was unprofessional

adverb plus other modifier (see 2.1)

publicly held securities

chemical terms, adjectival (see 2.11)

calcium nitrate deposit


  • Fowler, H.W., A Dictionary of Modern English Usage, pp. 255-258.

  • Garner, B.A., A Dictionary of Modern Legal Usage, p. 18.

  • Jarvie, Gordon, Bloomsbury Grammar Guide, pp. 9, 10, 23, 129-132.

  • Public Works and Government Services Canada, The Canadian Style, pp. 37-48.

  • Quirk, R. and Greenbaum, S. A., University Grammar of English, Appendix III.3.

  • University of Chicago Press, The Chicago Manual of Style, pp. 176 -179.