As with other aspects of the language, certain punctuation conventions can vary between BrE and AmE. This section will focus on the most common differences between the two variations. For a more detailed discussion of English punctuation in general, see the Practical Guide to English Usage: Comparing and Contrasting English and Catalan or the Interuniversity Style Guide for Writing Institutional Texts in English.
Commas
The serial, or Oxford, comma is used to set off the final item in a list of three or more items. It is placed after the penultimate item and before the coordinating conjunction (usually and or or). Examples:
Notwithstanding the reference to Oxford, the serial comma is more frequently used in AmE than in BrE, where it is generally used only when necessary to prevent confusion. For instance, in the famous example I would like to thank my parents, Ayn Rand and God, the lack of a serial comma could potentially lead readers to think that the phrase my parents was being used in apposition to Ayn Rand and God.
In general, it is UOC policy to follow BrE usage in this regard and not to use the Oxford comma except where required for clarity.
AmE also uses commas to format dates, whereas BrE tends to omit them. Examples:
The new ACUP board was appointed on Tuesday, January 24. (AmE)
Full stops (periods)
In BrE, full stops are used for truncations, but not for contractions. They are likewise omitted from initialisms. In contrast, AmE generally uses full stops for both contractions and initialisms. Compare:
| BrE | AmE |
| Dr | Dr. |
| Mr | Mr. |
| UK | U.K. |
| EU | E.U. |
Hyphenation
BrE often hyphenates compound nouns and adjectives that are written as a single unit in AmE. For example:
| BrE | AmE |
| break-up | breakup |
| mouth-watering | mouthwatering |
| north-east | northeast |
Likewise, BrE often uses a hyphen where AmE does not to separate prefixes from the words to which they are attached, particularly in cases where the final letter of the prefix and the first letter of the root word are the same or when omission of the hyphen could lead to mispronunciation. Compare:
| BrE | AmE |
| co-worker | coworker |
| pre-eminent | preeminent |
| re-enter | reenter |
Hyphens are generally used in both varieties of English to separate a prefix from a capitalized noun. Examples:
post-Renaissance
sub-Saharan
Likewise, both varieties often use hyphens to distinguish between words with distinct meanings that would otherwise be homographs, such as recreation (activity done for enjoyment) and re-creation (something created anew) or unionized (organized in a labour union) and un-ionized (not ionized).
Notwithstanding the above, in practice both varieties often accept both hyphenated and unhyphenated spellings of a single word. It is thus above all important to be consistent within each text. In other words, do not use pre-eminent on first mention and preeminent a few pages later.
As a general rule, for common words with both accepted hyphenated and non-hyphenated variants, the UOC recommends deferring to the Oxford Dictionary; hence, coordinate, email and online but e-learning and pre-empt.
Quotation marks and placement of end punctuation
AmE generally uses double quotation marks, or inverted commas, to indicate direct quotations and single quotation marks for nested quotations within them. It also generally places full stops and commas inside the closing quotation mark, although placement of other forms of punctuation (e.g. dashes, question marks, exclamation points) depends on whether they pertain to the quote itself. Example:
According to Mr. Esteban, the conference represents “a critical review of the adaptation of healthcare technology to the environment.”
“How many times have you heard him cry 'Impossible!' only to watch him go on to get the job done?” he asked.
BrE usage varies. Many influential BrE sources, such as Oxford University Press (OUP), essentially do the opposite of their AmE counterparts, using single quotation marks to indicate direct quotations and double quotation marks to set off any further quotations within them. Under this system, end punctuation is placed according to what is known as 'logical punctuation', i.e. punctuation is only placed before the closing quotation mark when it forms part of the sentence being quoted. Example:
According to Mr Esteban, the conference represents 'a critical review of the adaptation of healthcare technology to the environment'.
'How many times have you heard him cry “Impossible!” only to watch him go on to get the job done?' he asked.
Other reputable BrE source, such as The Economist, following a blend of AmE and BrE conventions, using double quotation marks for direction quotations and single quotation marks for nested ones, but following the same logical punctuation system followed by OUP and others. Example:
According to Mr Esteban, the conference represents “a critical review of the adaptation of healthcare technology to the environment”.
“How many times have you heard him cry 'Impossible!' only to watch him go on to get the job done?” he asked.
The UOC recommends following The Economist's guidelines for quotations in its texts. In short, use single quotation marks only for quotations inside quotations and place all punctuation outside unless it forms an integral part of the quoted text. For more information and examples, see the Interuniversity Style Guide for Writing Institutional Texts in English.
The UOC also recommends using single quotation marks to set off terms being used ironically or as slang or being introduced for the first time. Example: