Tips on Punctuating with a Colon in Academic and Scientific Prose
It is comforting to think that the association between scholarly writing and colons is based more upon the excellent use to which academics and scientists tend to put the colon as a vital piece of punctuation than to any whiffs of personality tendencies. Such reasoning would certainly be justified, for the colon (:) serves scholars in a wide variety of practical and stylistic ways. Indeed, if used well, it can not only help when citing sources and recording data, but also lend variety to sentence structure, encourage the forward movement of an argument and, quite simply, contribute to better writing practices. Among the many functions of the colon are the following:
• The colon is an excellent tool for introducing lists, quotations, translations, examples, explanations and the like in a clear and organised fashion. The colon is used after an independent clause, but the material that follows the colon need not be an independent clause or indeed of any particular structure or length. An embedded series of one-word elements, a displayed quotation of many sentences, a bullet list of items (as demonstrated by this article) and many other kinds and forms of information can be introduced by a colon.
• The colon can be used to punctuate between two independent clauses in a way that links them closely, places emphasis on the second clause and moves a report of information forward. In such cases the colon functions much as the words ‘namely,’ ‘for instance,’ ‘for example,’ ‘because,’ ‘that is’ and others do, and the second clause tends to offer an explanation, elaboration, illustration, description or example of what has gone before it.
• The colon is often used to punctuate the titles, headings and captions used in a document, where it tends to separate the main or catchier part of a title from the subtitle or more explanatory part, as it does in ‘Fragments, Fusions and Splices: Perfecting Sentence Structure,’ the title of another of my posts. Paragraph run-in headings used in structured abstracts and scholarly articles are sometimes followed by a colon (though sometimes by a full stop instead). When headings are numbered, a colon can be used between the number and the words that make up each heading (again, a full stop is another common choice for this position).
• Colons are used in scholarly references of various kinds in a variety of ways. Publisher guidelines will usually provide specific advice on where colons should be used for citations within a text – to introduce page numbers, for example – and also in the full references listed at the end, such as between the place of publication and the publisher.
• A colon is also used at the beginning of a formal speech, business letter or other professional communication immediately after the mention of those addressed – as in ‘Ladies and Gentlemen:’ or ‘To Whom It May Concern:’ or ‘Dear Editor:’ – but particularly in American English, so a comma is usually used for the same purpose in British English.
• A colon can be used to express a ratio. The colon is placed between two numbers, as in ‘a ratio of 2:1’ (two to one), or between two words, as in ‘the sugar:water ratio of hummingbird food.’ In either case, no spaces should appear around the colon.
• Colons are used when expressing precise times in numerals. In this context, a colon is used between the hours and the minutes, so 14:23 in the 24-hour clock would be 2:23 p.m. in the 12-hour clock. This usage tends to be North American, so the full stop will often replace the colon in British English (14.23 and 2.23 p.m.).
