Hyphens and the Compound Adjective

We’ve never tackled compound adjectives, here on One Step Forward, partly because it’s such a complex subject. Often you can make your sentence clearer by using an adjectival phrase or clause rather than worrying about whether to hyphenate. But today we’re going to ease your fears and explain just when to put that pesky hyphen between words in a compound adjective.

Here’s the short version: hyphenate when you place the compound adjective in the sentence before the noun.

This too-simple rule, however, does not address some specific kinds of adjectives. For instance, you would hyphenate a “one-week extension” but you would not add a hyphen to the possessive form, “one week’s extension”. And then there are compound adjectives that you write as a single word, a surefire way to confuse people.

Add to this the fact that, in a passive construction where the adjective end up as the predicate you still hyphenate. Thus you would write about a hard-core song, “This song is hard-core.” User-friendly programs are user-friendly.

Note that a compound adjective can consist of other parts of speech. You may have a noun and a participle, as with an attention-getting headline, or even a pair of nouns used to describe a third. The latter depends more on the nature of the words used than the placement. You would write about an African-American teacher but a Supreme Court decision, the space-time continuum but a real estate exam.

When the nouns refer to a well-known concept or an institution they need not be hyphenated. Thus a life insurance salesman does not require a hyphen while a roller-derby skater might. You may fill out your tax return form but only after performing a cost-benefit analysis.

“Wait!” you may cry. “Everyone knows what a cost-benefit analysis is.” But therein lies another wrinkle in the hyphenation question. Two nouns of essentially equal importance should be hyphenated when used as a compound adjective. Whether the social or the security means more, you still get a social security check if you qualify.

All of this ignores the fact that some pairs of words become a single, compound word and others do not. Skin diving stays just that when used as an adjective but skydiving is a single word. Housewarming parties get no hyphen but your house-sitter does. Adding more modifiers to a noun doesn’t change the hyphenation rules, either. The ever-popular, oft-misunderstood space-time continuum keeps all of those little dashes.

So how do you figure out whether to hyphenate commonly-used phrases? Sadly, the best answer remains the same thing your mother told you when you asked her how to spell something: look it up in the dictionary. Maybe someday I’ll be brave enough to tackle compound adverbs.

A Short Guide to Hyphen Use

Hyphens add an extra spice to general, punctuation-related confusion. Their rules allow exceptions on almost every side, rather than giving hard-and-fast guidance to hapless writers.

While there are exceptions to most of the rules that govern hyphens, you should know the general guidelines. You use them to compound words that have not been accepted as a single word. Thus, mother-in-law, head-to-head, mom-and-pop, and often-requested require hyphens. Except that the last example is hyphenated only when used as an adjective.

Here we come to the crux of the matter. You hyphenate a noun that contains a prepositional phrase, but not if the phrase modifies the noun. “Director of marketing” would not be hyphenated, as “of marketing” explains what the subject directs.

In contrast, a work-at-home dad needs his hyphens. “Work-at-home” modifies “dad” and acts as a single word in this example. You may have difficulty walking that fine line, at first. A little practice will help you decipher whether your phrase acts as a word.

A noun that functions in two or more roles also requires a hyphen between them. A writer-actor-director serves three functions (well or not) in the staging of a play and thus has earned his or her hyphens.

You use a hyphen when attaching a prefix to a proper noun. Anti-American sentiment, post-Reagan era, and quasi-French cuisine all must be hyphenated. Words that begin with ex-, all-, or self- also demand a hyphen. “The all-access pass that her ex-boyfriend left allowed her to act self-assured backstage.”

You also add a hyphen between some words comprised of a single letter and an actual word, such as T-shirt and X-ray. You don't, however, hyphenate I beam or T square. I could find no reason, other than conventional use, for the hyphenation difference between T-shirt and T square.

One more type of word requires hyphens: the compound number. When you write out two-digit numbers or the last two integers of a longer number, you add a hyphen between the words. Thus, I am writing this on the twenty-third day of February.

If you have some examples or other ways in which to use hyphens, please share them. If you have a terrific mnemonic device for remembering or figuring out how and where to use them, for the love of all that is holy, please post them below. Thank you!

You Learn Something New: Em-Dashes

I was incommunicado for a couple of days, without any computer access at all. I think I will recover fully, but it was touch-and-go last night. Please accept this complicated topic as reparations.

In response to a comment on my recent anti-semicolon post, I researched the difference between using an en-dash (a short dash that looks like a hyphen but is not a hyphen) rather than an em-dash (a long dash often represented by a double-hyphen). I came across a discussion about various type styles and dashes. The posts were written five years ago, but the discussion gives some good history.

I then found a surprising page about the en-dash versus em-dashes in singles, pairs, and trios. Each version has an appropriate set of uses and a special character. I had no idea!

I use en-dashes (hyphen-length) for em-dashes (double-hyphens that many word processors replace with a special character. I have done that for years because I think—as do several folks in the first discussion—that the double-hyphen construction is unattractive.

The special character (as seen in the previous sentence) does not appear magically on bulletin boards and fora. To avoid the ugly version, I began using the [space]hyphen[space] construction that you can see in other posts on this blog. MS Word automatically replaces that with an em-dash with a space on either side.

The problem is that the special character does not translate into a noticeably different-length dash in most HTML editors like the one for this blog. I never thought to review their appearance as posted rather than in the editor. The way I use en-dashes gets the point across but is technically incorrect. I am trying to break my bad habit, and thanks to Carradee for the “heads up”.

Does anyone else have a bad habit to explore, my oversight or yours?