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Grammar and Mechanics: Hyphens

Hyphen Basics

A hyphen is a punctuation mark that connects words.

Example: The peer-reviewed research suggested...
Example: As a fourth-grade teacher, I...
Example: Anderson (1998) tried to avoid face-to-face conflicts.
  • Review APA 7, Sections 6.11 and 6.12 as well as Tables 6.1, 6.2, and 6.3 for more detailed hyphen guidelines.

Use Hyphens...

  1. If a temporary compound can be misread.
    • “Adolescents resided in two parent homes” (APA 7, p. 162). For clarity, this can be rewritten as, “Adolescents resided in two-parent homes.”
  2. When there is a compound with a participle (i.e., verb ending in –ed or –ing) that precedes the term it modifies
    • evidence-based practice
  3. When an adjective-and-noun compound precedes the term it modifies
    • low-income families
  4. When a compound has a number as the first element and the compound precedes the term it modifies
    • 10th-grade students
  5. When a fraction is used as an adjective
    • one-fourth minority
  6. When two or more compound modifiers have a common base
    • long- and short-term memory
  7. When the base word in the compound is capitalized
    • Likert-type scale
  8. When the base word is a number
    • pre-2010
  9. When the base word is an abbreviation
    • pre-CDC recommendation
  10. When the base word is composed of more than one word
    • non-peer-reviewed research
  11. When “self” is used as the compound
    • self-report
  12.  When words could be misunderstood
    • re-pair (to pair again)
  13. When the prefix ends and the base word begins with “a,” “i,” or “o”
    • meta-analysis
    • co-occur

Do Not Use Hyphens...

  1. When the compound follows the word it modifies.
    • Incorrect: The research was peer-reviewed.
    • Correct: The peer-reviewed research...
  2. With compound adjectives when they cannot be misread or when their meaning is established (a permanent compound)
    • health care reform
  3. With compounds including an adverb endling in “-ly”
    • widely distributed information
  4. With compounds including a comparative or superlative
    • higher order learning
  5. With chemical terms
    • biochemical oxygen demand
  6. With Latin phrases use as adjectives or adverbs
    • post hoc test
  7. With modifiers including a letter or numeral as the second element
    • Type II diabetes
  8. With fractions used as nouns
    • three fourths of the participants
  9. With prefixes “pre” and “re” when the base word begins with an “e”
    • preexisting
    • reexamine
  10.  With most prefixes and suffixes.
    •   The unbiased study displayed multifaceted information about agoraphobia.


Here is a list of prefixes and suffixes that do not require hyphens (taken from APA 7, Table 6.2):

  • able
  • after
  • anti
  • bi
  • cede/sede/ceed
  • co
  • cyber
  • equi
  • extra
  • gram
  • infra
  • inter
  • like
  • macro
  • mega
  • meta
  • meter
  • micro
  • mid
  • mini
  • multi
  • non
  • over
  • phobia
  • post
  • pre
  • pseudo
  • quasi
  • re
  • semi
  • socio
  • sub
  • super
  • supra
  • un
  • under