This is the last Tuesday’s Tip for the holidays; I’ll be back Jan. 8!
There are several instances when writers need to use a hyphen. Essentially, hyphens are used when two or more words need to be joined together as one block; think of hyphens as links. The exact rules for when to use a hyphen are:
- Joining compound modifiers (e.g., first-rate, six-year-old)
- Joining compound numbers and fractions (e.g., sixty-five, two-fifths)
- Attaching some prefixes to root words (e.g., ex-wife, post-World War II)
- To avoid confusion (e.g., re-mark vs. remark)
Compound modifiers are words that must be used together, in a particular order, to describe another word. For example, I could describe “the old, gray truck”; “old” and “gray” would not be a compound modifier because they make sense independently (“the old truck” and “the gray truck”) and in any order (“the gray, old truck”). However, if I am talking about someone having a “part-time job,” it is a compound modifier because both “part” and “time” must be together, and in that order, to make sense; a “part job” makes no sense, nor does a “time part job.” Therefore, you must hyphenate “part-time.”
All numbers that are spelled out, including fractions, must be hyphenated.
The prefix rule can be confusing because only some prefixes are hyphenated. Always use a hyphen before the prefixes “self,” “all,” and “ex.” Use a hyphen between a prefix and a common noun if the prefix ends in the same letter that the noun starts with; e.g., re-elected, anti-intellectual. And always use a hyphen between a prefix and a proper noun; e.g., un-American, pre-Columbian, mid-January.
Finally, use hyphens between prefixes and words to avoid confusion about meaning. For example, a doctor may need to re-treat an infection; “re-treat” does not mean the same as “retreat.” Other examples include repress and re-press, recreation and re-creation, re-mark and remark.