A compound adjective is a modifier made up of two or more words. The general practice in writing is to use a hyphen if the compound adjective can be misread. There are several exceptions to this rule. The best reference for confirming whether to hyphenate or not hyphenate a word is Webster’s dictionary (11th edition). Here are five rules for using the hyphen.
Use a hyphen with comparative and compound adjectives (words ending in er and est).
Examples: longer-term study, best-qualified candidate, highest-rated schools.
Use a hyphen in a temporary compound adjective (one that is made up of specially chosen words to best describe something). The hyphen is a crucial tool to give clarity and help readers understand your message. Use it if the word can be misread to change the meaning of your sentence.
Example: The students resided in two parent homes. (This implies two separate residences.)
The students resided in two-parent homes. (This implies that they lived in a home with both of their parents.)
Example: The used-furniture store is popular with students. The hyphen in this case shows that the store sells used furniture.
Whereas “The used furniture store ” implies that the furniture store is used by students.
Use hyphens for compound words in which the second word is capitalized.
Example: The program will operate from mid-June to the end of August.
When there is a prefix before a date.
Example: The pre-1945 movie was not included in the curriculum.
Example: The pro-MADD parents sponsored after-prom activities for the seniors.
Several related words.
Example: The non-school-based employees work for 12 months of the year.
Words that could easily be misunderstood.
Example: re-form (to form again)
Most words formed with a prefix or suffix are written as one word.
Examples: Prefix: extracurricular, socioeconomic, prekindergarten (BUT pre-K), counterclockwise
Suffix: ladylike; courthouse
If a compound adjective is placed after the term it describes, do not use a hyphen, since the combination is clear enough for readers to understand.
Examples: the student-centered activities are new this year, BUT this year, the new activities are student centered.
The program was designed for same-sex children. BUT The program was designed for children of the same sex.
When two or more compound adjectives have a common base, the base is often omitted in all but the last adjective, but the hyphens are retained, followed by a space.
Examples: Long- and short-term measures, over- and underfed hamsters, 15- and 30-year mortgages.
Get more help with hyphenation and putting your best word forward. Visit editsbymarks.com and send me a note.
I am a little lost with the implication that “the furniture store is used by students”.
Good point. However, some people might well read it as the furniture store is used by students. So, it’s best to be as clear as possible.