- When the compound follows the word it modifies.
- Incorrect: The research was peer-reviewed.
- Correct: The peer-reviewed research...
- With compound adjectives when they cannot be misread or when their meaning is established (a permanent compound)
- With compounds including an adverb endling in “-ly”
- widely distributed information
- With compounds including a comparative or superlative
- With chemical terms
- biochemical oxygen demand
- With Latin phrases use as adjectives or adverbs
- With modifiers including a letter or numeral as the second element
- With fractions used as nouns
- three fourths of the participants
- With prefixes “pre” and “re” when the base word begins with an “e”
- 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