November 7, 2013
Weekly Language Usage Tips: Using hyphens with compound words
Tip: Using hyphens with compound words
A reader writes:
Engaging Patients at the Point-of-Care
Use the dashes in the word?
This issue has come up a few times lately. This is the answer I wrote back.
Nope. No dashes. You use hyphens when the word is used as an adjective, not as a noun (e.g., end-of-life care, decisions at the end of life).
And it’s true, but it’s not the whole story, so I thought I would explain it a bit more today. Talking about hyphens seems to be an annual event. And it’s a happy event for me, because hyphens need all the publicity they can get. They are woefully under-used. [NOTE: Doesn’t that sound better than underutilized?]
First, let’s review some definitions. Dashes and hyphens are not the same. The little line on your keyboard between the plus sign and the zero keys is the hyphen. Dashes are special characters. There is the em dash, and there is the en dash. They are named for how big they are. The em dash is the size of an m (—). The en dash is the size of…well, you can figure out the rest (–). The hyphen is the smallest of the three (-). Briefly, em dashes are used to separate parenthetical statements from the rest of the sentence (Planning of pilot studies takes significant collaboration between investigators and biostatisticians—we use the statisticians at the Center for Research on Health Care—to identify the optimal design.). En dashes usually show a range (6–10 feet, open from June–September). Hyphens are used for other things such as forming compound words, linking prefixes to a word, showing word and line breaks, and to clarify or avoid confusion.
Today, we are talking about hyphens with compound words. Okay, here’s another definition. A compound word is a group of two or more words that are combined to form a single concept. They can be formed with hyphens (e.g., decision-making rules), by melding the words (e.g., schoolhouse), or they can be left open (e.g., high school). There are no real rules about using hyphens with compound words, but there are conventions. And here they are:
- As noted above, you use hyphens when the word is used as an adjective, but not when used as a noun.
- The exception comes when the compound adjective follows the noun; generally, there are no hyphens in compound adjectives that follow the nouns they are modifying (e.g., the treatment was patient centered vs. patient-centered treatment).
- Use hyphens in the compound word when the first word or prefix ends with the same letter as the main word (e.g., this meta-analysis).
- Use hyphens when there could be confusion or a chance of misunderstanding (e.g., cross-cutting practices vs. cutting practices that are angry).
That should about do it. As I said, these are conventions, not rules, but they are worth following. And if you can only remember one, remember the first one, and you are unlikely to go wrong.