A compound noun is the combination of two or more existing nouns or other parts of speech Opens in new window used together to express a single meaning. They are part of one unit and have become a set phrase.
Compound nouns usually consist of two nouns such as foot + ball. They vary in form; some are closed, some are open, and some are hyphenated.
The following are examples of compound nouns:
|Closed Forms||Open Forms||Hyphenated Forms|
In compound nouns, the first word is usually stressed, and the two words are said together, with no pausing in between the words.
Forms of Compound Nouns
1. NOUN + PRESENT PARTICIPLE
Some compound nouns are a combination of a noun and a present participle Opens in new window (the –ing form of a verb), written as two words. However, some are written either as open or closed compounds, while others are separated by a hyphen.
|Open Forms||Closed Forms||Hyphenated Forms|
If you are uncertain as to which choice to adopt, consult your dictionary. And if the dictionary happens to show two options, for example, baby–sitting and babysitting, adopt the option that suits your style.
If however, the particular compound is not listed in the dictionary and you can’t find a similar compound to compare to, you may resolve to write the compound as two words.
2. VERB + ADVERB
Compound nouns which are a combination of verb and adverb are usually written closed or hyphenated. Several of these forms can be written both ways.
These particular compounds require extra effort to remember the appropriate pattern of writing them.
Different dictionaries, we have observed, show different spellings, as even grammar experts tend to disagree in this particular area.
Note that regardless of how these combination of verb and adverb compound nouns are spelled, these same expressions are written as two separate words when serving as verb phrases. Note the following:
- The CDC is investigating a possible Ebola breakout in Reston.
- I noticed it during my initial size–up.
- Break out the Level A chemical suits.
- Let me size up the situation.
3. COMPOUND WITH A LETTER
Sometimes a lone letter is combined with a word to express one meaning. When this happens, a hyphen is usually used to separate the two.
However, when the connection between the two is clear without a hyphen, the compound may be written in open form.
|O–ring||T cell||T–shirt||U bolt|
|x–ray||x ray||X ray||X–ray|
4. PHRASES AS COMPOUNDS
Some phrases Opens in new window serving as compound nouns are usually hyphenated:
|a free–for–all||a good–for–nothing|
|a pick–me–up||a stick–in–the–mud|
Most compound nouns formed from repeated or rhyming words are usually hyphenated:
5. POSSESSIVE NOUN + NOUN
This particular form of compound nouns consists of a possessive noun followed by another noun and are usually written in open form. However, some are written in hyphenated form. A few of this form take the closed form (and written without the apostrophe).
|fool's gold||hornet's nest||bird's–eye|
And the following, which can be written either open or closed:
|men's wear||women's wear||menswear||womenswear|
6. Names and Titles
Proper nouns in this form are often written open:
|Central American||French Canadian|
|Native American||Middle East|
The compound is written hyphenated if it contains a prefix or combining form in place of a full word:
Family titles containing great or in–law are always separated by a hyphen:
Job titles containing man, men, woman, or women are usually written closed.
However, while it is acceptable to use these terms when referring to a specific person, it is a preferable practice to replace these titles with terms that do not suggest gender specification:
|Gender Specific||Non Gender Specific|
Civil and military titles are typically not hyphenated:
|attorney general||chief of staff|
|lieutenant governor||chief of police|
|sergeant at arms||commander in chief|
|some with exceptions:||ambassador–at–large||attorney–at–law|
When it comes to compound titles containing the prefix ex– and the suffix –elect, and forms containing vice; hyphens are usually applied to separate the compounds:
|Either hyphens or slashes may be applied to indicate combined titles:|
GUIDELINES TO FOLLOW
1. While a number of compound nouns are hyphenated in form, the majority are either closed or open.
Some compound nouns are often written closed when they are short, when they are commonly used, and when the accent is stressed on the first syllable:
2. Short compound nouns tend to be written open when the accent is not heavily stressed on the first syllable.
|alarm box||blood cell||blue devil||dead time|
|fire truck||hot spot||leg wound||red alert|
|short circuit||time bomb||waste product||yellow fever|
3. Similarly, longer compound nouns, are usually written open.
|automatic weapon||chemical reaction||disaster planning||drug interruption|
|internal bleeding||malicious mischief||probable cause||nitroglycerin tablet|
|respiratory distress||sprinkler system||unlawful entry||water damage|
Note that some compound nouns can be written in more than one way: (high-rise, high rise, and highrise). In such a case, we recommend you implement the style that suits you and be consistent with it.