Colons can be used to divide two clauses (or parts) of a sentence. They’re useful because they can help to reinforce or expand upon information that has already been stated. For example:
Luton Town are performing poorly in League Two: they are currently twelfth in the table.
Here, a colon has been used to expand upon the information provided in the first half of the sentence. We now know that poor performance for a prestigious football club like Luton Town is defined by a mid-table placement and not, say, a place in the relegation zone.
A carefully placed colon can also help to add clarity – perhaps even a literary flourish – to your writing. Here’s an example from Wolf Hall, by Hilary Mantel:
‘These days it is nothing but Frenchmen about the king, and she, Boleyn, she is half-French herself, and wholly bought by them; her entire family are in the pocket of Francis. But you, Thomas, you are not taken in by these Frenchmen, are you? He reassures him: my dear friend, not for one instant.’
The novel is about the reign King of Henry VIII and, in particular, the rise in status and influence of his advisor, Thomas Cromwell. Much of the novel focuses on Henry’s desperation to divorce his first wife, Catherine of Aragon, and his desire to marry Anne Boleyn. In the quote above, Eustace Chapuys, the Spanish ambassador, is reflecting on the shifting balance of power in Henry’s court and, more widely, upon the increasingly strained relationship between England and Spain. The first sentence is fragmented: a sense of Chapuys’s uncertainty and discomfort is conveyed. In contrast, however, the colon in the second sentence offers clarity and helps to amplify the confidence and authority with which Cromwell is able to offer reassurance to Chapuys. Outwardly, he is embraced as a dear friend by Cromwell – a loyal ally – or so it seems.
Here’s one more example of how a colon can be used to add clarity, taken this time from The Song of Achilles, by Madeline Miller:
‘This is what Achilles will feel like when he is old. And then I remembered: he will never be old.’
The novel is a retelling of the Homeric epic the Iliad and focuses on the romantic relationship between Patroclus and Achilles. Achilles, the son of a goddess and a mortal man, is a demi-god and can only be harmed in his heel. The relationship between the two men is at least partly defined by their shared understanding of what this means: their time together is finite and they will not be able to embrace the aging process together. In the quote above, the colon marks the transition in Patroclus’s thought process from untroubled reverie to his reengagement with this bleak reality.
And so… If Henry VIII’s bitter first divorce from his dutiful Spanish wife and a tale of two troubled Greek warriors has inspired you to find out more about how and why colons are used, why not click on the link below?
TL;DR: a colon can be used to help reinforce or expand upon information that has already been stated.