prefixes

As a general rule, do not use hyphens with well-known prefixes such as anti-, bi-, multi-, non-, post-, pre-, pro- and uni-, or if the base word starts with a consonant (antihistamine, multidisciplinary, nonprofit, predoctoral, postoperative, postgraduate).

If the prefix ends in a vowel and the word that follows begins with the same vowel, a hyphen is required (anti-inflammatory). Exceptions: cooperate, coordinate, preeclampsia, preeminent.

Also use a hyphen when the addition of a prefix results in two conjoined vowels or repeated letters that impede readability (bio-adhesive, pre-registration).

Use a hyphen if the base word is capitalized (non-English-speaking).

When using the prefix co-, include the hyphen when the word describes occupation or status, or when the hyphen is needed for readability (co-author, co-chair).

When using the prefix self-, always use a hyphen (self-care, self-evident). See also hyphens.