A compound consists of two or more words that express a single concept. A compound word may act as a noun, a verb or an adjective, or even all three.
There are a few different types of compounds:
|Open compounds||Words written separately with a space between them||time frame|
|Closed compounds||Words run together with no space separating them||crossbreed|
|Hyphenated compounds||Words linked with a hyphen||hand-feed|
Would that there were predictable rules governing the compounding of words; there aren’t. This means you need a good dictionary to check the proper compounding of words. (I use Merriam-Webster’s Unabridged Dictionary.)
Note also that language changes constantly. Words often begin as hyphenated compounds and then eventually drop the hyphen, becoming closed. (For example, over the past twenty years, e-mail has become email.)
Stilman states, “Compound nouns that comprise more than two words, such as idioms and phrases, usually take hyphens.” For example: He’s a Johnny-come-lately. Check a dictionary or a reliable list of idioms.
If a word is compounded with a single letter, it is either open or hyphenated (not closed): A-frame, B picture, T square, H-bomb, V neck.
Some compound nouns can be closed or hyphenated, such as carry-over/carryover, short-list/shortlist. Again, check the dictionary.
When you use more than one adjective to modify a noun, sometimes they must be linked with a hyphen to ensure clarity. For example, there’s a difference in the meaning of these sentences:
- Seven week old kittens mewled in the cardboard box. (One or more of the adjectives must be hyphenated to make the meaning clear.)
- Seven week–old kittens mewled in the cardboard box. (Seven kittens, all one week old, are mewling in the box.)
- Seven–week–old kittens mewled in the cardboard box. (An indeterminate number of kittens, all seven weeks old, are mewling.)
Compounding adjectives deserves a post of its own, so subscribe and check back later for another lively discussion.
Compound verbs are usually open but are sometimes closed or hyphenated. Often, a closed noun compound becomes open when used as a verb compound. For example:
- She experienced a breakthrough. (closed compound noun)
- She wanted to break through her crippling grief. (open compound verb)
Some hyphenated compound nouns become open when used as verbs, for example, show-off/show off.
When verbs are compounded, it is often between the verb and some kind of direction word: back-check, stick up, break down, make up. When verbs are open compounds, the space often comes between the verb and a preposition: break through, stand in.
Commonly Mishyphenated Words
Stilman lists a number of words and phrases that are often hyphenated but shouldn’t be. These include: more or less, ongoing, a priori, ad hoc. Latin phrases should not be hyphenated.
Next time, we’ll take a closer look at hyphenation in prefixes and suffixes. I’ll bet you can’t wait!
Source: Anne Stilman’s Grammatically Correct: The Writer’s Essential Guide to Punctuation, Spelling, and Grammar (Writer’s Digest Books, 1997).