Using Hyphens in Compounds

Hyphens can be confusing, especially when you see the same set of words both with and without them. So, when should you use up-to-date or up to date? It’s simpler than you think!

Today we are focusing on two places we often see hyphens used in: compound modifiers and hyphenated compound words.

Compound Modifiers

Compound modifiers, or adjectives, work exactly how you expect: to modify a noun. Anywhere you could use a normal adjective, you can also use a compound modifier. Typical compound modifiers comprise a noun + an adjective, a noun + a participle, or an adjective/adverb + a participle. The main rule to remember when writing is if the modifier comes before the noun, use a hyphen; if it comes after the noun or the verb, do not use a hyphen.

Let’s look at some examples.

Noun + Adjective à noun being modified

Sugar + free à Coke

Is this sugar-free Coke?

Is this Coke sugar free?

Carbon + neutral à buses

My city only has carbon-neutral buses.

My city only has buses that are carbon neutral.

Noun + Participle à noun being modified

Solar + powered à neighborhood

There is a proposal for a new, solar-powered neighborhood.

There is a proposal for a new neighborhood that is solar powered.

Family + run à businesses

Congress introduced a bill in support of family-run businesses.

Congress introduced a bill in support of businesses that are family run.

Adjective/adverb* + Participle à noun being modified

*Note that adverbs ending in -ly are never hyphenated but adjectives ending in -ly are commonly hyphenated

Above + mentioned à document

The above-mentioned document will be preserved for posterity.

The document mentioned above will be preserved for posterity.

Well + known à author

My father was very upset he couldn’t meet the well-known author.

My father was very upset he couldn’t meet the author who was well known.

You might notice that while these sentences are all grammatically correct, the second sentence (where the modifier comes after the noun) tends to require more words or even a rearrangement of words to be expressed correctly. The benefit of using compound modifiers with hyphens is concise and precise writing. And remember, there are always exceptions!

Hyphenated Compound Words

Unlike compound modifiers, hyphenated compound words always have hyphens, regardless of where they appear in a sentence. Common words include mother-in-law, merry-go-round, good-looking, etc. These, like all vocabulary words, simply need to be memorized. Of course, it is recommended you check them in the dictionary every couple of years because it is not unusual for hyphenated compound words to evolve into closed compound words (such as the change from good-bye to goodbye). Some compound words even are grammatically correct when written in different ways, such as child-care or childcare. When you are writing, the most important thing is to choose one version and use it consistently throughout.

If you are ever in doubt as to whether a word or a group of words should be hyphenated, and the dictionary hasn’t been of any help, always consider the clarity of what you have written is. Hyphens help connect words so that there is no doubt as to what is being described.

Take the phrase “10 year old.” Without the hyphens, the reader does not know if there is only one person who is ten (written 10-year-old) or if there are 10 people who are one (10 year-old). Of course, much of this confusion could be avoided based on context in the sentence, but it can still be unclear, especially in translated works. You never want to leave a reader wondering if there was a mistranslation or an editing error.

In conclusion, I hope your knowledge of hyphens in now up to date and you can start writing with confidence-filled gusto! Until next time!