A compound word is made of two or more words that together express a single idea.
a. An open compound means that the words of the compound are written separately, (New Year’s Eve, credit card, sea salt).
b. A hyphenated compound separates the words by hyphen(s) (brother-in-law, high-maintenance, force-feed).
c. A solid compound is formed when the two words are written as one word (typewriter, breakfront, oatmeal). Solid compounds generally begin as two separate words, then start to be used as hyphenated words, and finally become solid compounds (one word).
Compound words may be permanent or temporary. A permanent compound has been used so often and so widely that it is now in common usage and can be found in the dictionary. A temporary compound is one that joins words by hyphen(s) as needed, we can create our own temporary compounds. They say what WE want to convey to the reader.
Why do we even bother with a hyphen? To avoid confusion. When we join an adjective to a noun to create a compound adjective, without a hyphen the reader isn’t sure what is describing (modifying) what. A tall tree stump indicates that the stump is from a tall tree, but if you are writing about the tall stump of a tree, a tall-tree stump tells people that the stump was tall. The hyphen makes that clear.
Incorrect: The short legged dog ran for the door. (You are saying that the dog is short and had legs!)
Correct: The short-legged dog ran for the door. (Now you are saying that the dog’s legs are short.)
Incorrect: Her red orange car was easy to see from a distance. (Was the car red or orange?)
Correct: Her red-orange car was easy to see from a distance. (Now you are saying that the car was a color that was a combination or red mixed with orange.)
**If you use an “ly” adverb with an adjective, you do not need a hyphen. It is evident that the adverb modifies the adjective and NOT the following noun.
Incorrect: The incredibly-handsome man was also very vain.
Correct: The incredibly handsome man was also very vain. (The man was handsome, but the handsomeness was incredible.)
If the adjectives are capitalized, as in a film, book, speech, article, or song title, you DO NOT use the hyphen between them.
Correct: Professor Knoital’s lecture was entitled “The Wildlife Management Philosophy of Our National Park Service.” If the words are not in a title or capitalized, you hyphenate: The subject of Professor Knoital’s lecture was wildlife-management philosophy.
Correct: Marla was thrilled to be chosen for ISU’s prestigious Writers Workshop.
Correct: Marla wanted to attend a university with a good writers-workshop program. (This is a general type of program, not a specific program, so the hyphen is needed.)
More Notes on Compound Adjectives:
Compound adjectives formed with 1) an adverb plus an adjective or a participle, 2) an adverb or a noun plus a past participle, or 3) a noun, adjective, or adverb with a present participle are always hyphenated when they come before the noun: a well-liked President, the well-written essay. red-cheeked child, ice-covered streets, a great-looking car. IF the compounds come after the noun, they are not hyphenated. The President was well liked. Her essay was well written. The child was red cheeked. All the streets are ice covered. That car is great looking! Sometimes these compounds become permanent, and are hyphenated even after the noun, sometimes they become permanent solid compounds (merge into one word). That’s why it’s important to use your dictionary if you have any doubt at all.
Compound adjectives using an adjective and a noun to which -d or -ed has been added: blue-eyed man, curly-haired woman, multi-grained bread. Some of these compounds become permanent hyphenated or solid compounds after years of use.
Compound adjectives using these words are always hyphenated—before and after the noun: half, all, quasi, full, self, ex. Some compounds using “half” have become solid compounds--check your dictionary
Compound using these words are hyphenated before the noun, but not after the noun: well, ill, better, best, little, lesser, least. If the compound adjective is modified by an adverb, do not use hyphens--
Compound adjectives formed with “high”, “ low”, “upper”, “middle”, “lower” are usually hyphenated: low-rent district, high-ticket items, middle-management, upper-end income..
Many compound adjectives using “cross” are hyphenated, but some have become permanent, solid compounds (merged into one word—crosscut, crossover, etc.)
2. Compound Nouns are two-part nouns. They might be one word, hyphenated or two words. You need to check your dictionary. If the compound noun isn’t in the dictionary, write it as two words.
fast-food set-up keyboard breakfront swimming pool
More Notes on Compound Nouns:
An open compound noun (remember that an “open” compound means two separate words) that has an adjective in front of it, is often hyphenated. hen house—abandoned hen-house; milk cow—spotted milk-cow; night train—slow night-train.
Compound nouns made up of a noun and a gerund (remember that gerunds are verbs ending in “ing” that act as nouns) are generally open: deer hunting, back scratching, ditch digging. These may also become permanent solid compounds over time. bookkeeping, faultfinding.
Compounds made from two proper nouns that are designations of ethnic groups are usually NOT hyphenated (Latin American, French Canadian), but sometimes they ARE hyphenated, and there seems to be no set rule. Dictionary anyone??
If two nouns are of equal “weight” are put together for a compound, and the thing or person being described has characteristics of both, hyphenate the compound. President-CEO, writer-lecturer, soldier-statesman. However, two-word occupations are open (no hyphen): surgeon general.
Compound nouns using “master” are usually open compounds (two words), but some have become permanent. Check your dictionary!
Words of relationship with a noun are two words. mother ship, fellow traveler, father land.
Noun compounds using “quasi” are always open, but if “quasi” is used in a compound adjective it is hyphenated before and after the noun: quasi comedian but quasi-comedic act.
Compound nouns using “in-law” are always hyphenated, mother-in-law, brother-in-law, cousin-in-law, etc. In addition, relatives having “great” in their designation are always hyphenated. great-uncle, great-great-grandfather, etc.
Compound nouns formed with “elect” are hyphenated—president-elect, councilman-elect. If the name of the office is two words, such as county supervisor or state senator, check your dictionary or style sheet. There are differing opinions on whether to hyphenate or not.
Compound nouns with the suffix “ache” are always one word: stomachache, backache, etc.
Compounds may change in form depending on the way they are used. Somebody left the left the light on. Some body was missing from the morgue. Anyone can apply. Any one of those actors could play the part well. Everyone is here now! Every one of us had a good time tonight.
Scientific compounds are usually not hyphenated: calcium chloride, aluminum oxide, ethylene glycol.
Compounds with “book”, “fold”, “like”, “over”, “under”, and “house” are almost always closed (one word). Check your dictionary. “mid” is closed unless it is used with a number or a proper noun--mid-American values, mid-1960’s music.
3. Compound Verbs are a verb with a non-adverb. They can be one word or hyphenated. If you dictionary doesn’t list the compound verb, hyphenate it.
down-shift upgrade overkill freeze-dry
Phrasal Verbs are formed with a verb and an adverb (this is the most common structure, there may be articles and objects in the formation also). The phrasal verb is always two (or three or four) separate words.
put down go out pick up bring back get off
NOTE: When a short verb plus a preposition is used as a noun, it is written as one word or hyphenated. When the same words are used as a verb (phrasal verb), they a written separately.
The joke was a setup. The caterers set up the banquet at 4 pm.
Her comment was a putdown. She put down the gun and surrendered.
4. Phrases that are used as modifying compounds are hyphenated before the noun: He had a down-in-the-mouth look. Some folks have a what-the-hell attitude. After the noun the hyphen is not used: He looked down in the mouth. Her attitude was one of what the hell.
Prepositional phrases that describe a person are also hyphenated. Jack of all trades, hell-on-wheels, ball-of-fire
Foreign phrases used as modifiers are NOT hyphenated: a sub rosa deal, They offered an a la carte menu, an ad hoc committee.
5. Numbers can be used in compounds also, whether in numerical or word form.
As noun compounds: twenty-three, eighty-eight--any number from twenty-one to ninety-nine.
As adjective compounds: December thirty-first, third-degree black belt, 1000-piece puzzle, one-man show, 24th-century technology. When you use a number, a unit of measurement, and another adjective before a noun, hyphenate all three word: 16-year-old girl, forty-mile-long drive, ten-inch steel spike, but The girl was 16 years old. The drive was forty miles long. The spike was 10 inch steel.
Numbers written out when used with “fold” are not hyphenated; figures and “fold” are hyphenated: twofold, 10-fold.
Numbers used with “odd” are hyphenated: 13-odd, thirteen-odd.
If a compound consists of a number and a possessive noun, it is NOT hyphenated: two week’s vacation, three month’s work.
Modifying fractions are hyphenated unless part of the fraction already contains a hyphen or if the fraction is used as a noun: three-fourths asleep, but forty-four thousandths of an inch. The skirt was one-third stained, but One third of the skirt was stained.
6. Compound color adjectives are hyphenated: the blue-green lake, a peachy-pink dress. If the first color mentioned ends in “ish”, they are hyphenated before the noun they modify, but not after: his greenish –yellow shirt—his shirt of greenish yellow. The darkish- grey sedan—the sedan was darkish grey.
7. Prefixes and Suffixes are not exactly compound words in the sense of the other types talked about above, but because they are sometimes hyphenated, let’s toss them in here also. The general rule is to add a prefix and/or a suffix to a word WITHOUT hyphenating, unless it would double or triple the same vowel or consonant in the resulting word: antiaircraft, anticlimax, reorder, but anti-intellectual, re-educate and catlike, but jewel-like. Some prefixes, however, are added without the hyphen, even though that creates a double vowel or consonant: cooperate, reelected, overrated for example.
Use a hyphen when the word following the prefix is capitalized or if it is a number: pro-French, ex-Russian, half-Spanish, late-20th century, early-1700’s.
Two more tips
1. Some words are spelled the same, but have different meanings and may or may not pronounced differently (homographs). For these, you may need to add hyphens to avoid pronunciation mistakes and mistaken meanings:
recount (to tell or narrate in detail), re-count (to count or tally again),
reproof (reprimand, criticize), re-proof (to check a written work for errors again),
rejoin (to respond, retort, reply), re-join (to reunite or join again),
multiply (increase in number), multi-ply (more than one layer of cloth, paper, wood, or strands in a cord).
coop (a farm building for housing poultry), co-op (a jointly owned business run for the benefit of its owners, e.g. food co-ops, farmers grain co-ops)
If you add a prefix to a compound word that is already hyphenated, you still need to hyphenate the prefix. un-self-conscious.
2. Some permanent solid compounds change to open compounds if a hyphenated adjective is added. Homebuilder is a permanent compound (shown as one word in dictionaries), but if you write an ugly homebuilder, that means the person who builds the homes is ugly. If that was NOT your intent, you need to write it as an ugly-home builder. Then it is clear that the homes are built are ugly.
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