Prefixes

Many words beginning with a prefix are written with a hyphen (co-payment); many are not (overproduction). Confusingly, there are also cases where both forms are considered acceptable (British: pre-school / American: preschool). As can be seen from this last example, the tendency in American English is to hyphenate less than in British English. In any event, if in doubt about whether a prefix should be followed by a hyphen, consult a reliable dictionary. However, the following observations generally hold.

Words beginning with a common prefix (such as un-, dis- or re-) are often written without a hyphen.

Exemple adequatCurrent levels of absenteeism in many subjects are unacceptably high.

Exemple adequatStudent representatives have disregarded criticism from the Rector, calling it uninformed and unfair.

Exemple adequatThis initiative reaffirms the strong ties between the two universities.


Nevertheless, make sure to hyphenate when the prefix re- precedes a word beginning with e, such as re-evaluate, or when the hyphen can help avoid confusion, such as re-sent vs resent or re-sign vs resign.

Hyphenate all words formed by a prefix and a word beginning with a capital letter.

Exemple adequatThis movement is a pan-European response to failures in education.

Exemple adequatThe research confirms a growing anti-British sentiment in commercial relations.

Exemple adequatThe trans-Siberian railway attracts many students seeking adventure.


But note that words like transatlantic, transpacific or subarctic are normally written as single words with no capitalization.

Universitat de Barcelona. Serveis Lingüístics
Darrera actualització: 23-6-2023
Recommended citation:
«Prefixes» [en línia]. A: Llibre d’estil de la Universitat de Barcelona. Barcelona: Universitat de Barcelona. Serveis Lingüístics. <https://www.ub.edu/llibre-estil/criteri.php?id=2272> [consulta: 27 novembre 2024].