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 all events, 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.
 |
Current numbers of absences from class in many subjects are unacceptably high. |
|
Student representatives have disregarded criticism from the Rector, calling it uninformed and unfair. |
|
This initiative reaffirms the strong ties between the two universities. |
In contrast, a hyphen is generally used with prefixes such as neo– and ex-.
|
The Arts Faculty building is an outstanding example of neo-classicalarchitecture. |
|
Dr Rovira is the ex-director of the Cancer Research Institute. |
Hyphenate all words formed by a prefix + word beginning with a capital letter.
|
This movement is a pan-European response to failures in education. |
|
The research confirms a growing anti-British sentiment in commercial relations. |