Colons and semicolons are very useful marks which help writers to clarify exactly what they mean, and each has its own distinct function.

How and when to use a colon

The colon (:) is used to indicate that what follows is an explanation or elaboration on what has preceded. Having introduced a subject, you can add more specific information after the colon.

A colon is usually preceded by a complete sentence, but what follows the mark could be anything from a sentence to a list to a couple of words.

Examples of how to use a colon correctly

‘We could all see the problem: there just weren’t enough people to get the job done on the day.’ (Here the problem is explained)

‘Emily was facing a highly stressful situation: walking into an exam she hadn’t revised for.’ (Here the situation is set out).

‘Paul never forgot his mother’s mantra: never complain, never explain.’ (Here the mantra is quoted)

‘There were three men involved in the altercation: Rob Robertson, Ian Smilie and Darren Henderson.’ (Here we name the men in question)

Occasionally the colon construction is turned round, with the specific information laid out first and the general information after the mark

‘Red, yellow, pink, green: many of the colours of the rainbow could be found in the painting.’

As with all inverted constructions, this option will read badly if used too often.

How and when to use a semicolon

The semicolon (;) is used to join two complete sentences in a single written sentence under the following circumstances:

* Two complete sentences are closely related, but a full stop would be too strong a pause
* There is no connecting word which would require the use of a comma

A semicolon can always, in principle, be replaced either by a full stop (forming two separate sentences) or by a conjunction, such as ‘and’ or ‘but’.

An example of a correctly used semicolon

‘My son likes bananas; my daughter prefers apples.’

A semicolon would be impossible in the following example, however, since the sequence after the comma is not a complete sentence

‘The rat poison was working, almost too well.’

Finally, semicolons can also be used in a complex list, where each item on the list includes longer pieces of information and/or commas, so the semicolons can act like commas in a simple list.

‘We wanted to eat Christmas cake in December and January and February; Simnel cake in March and April; and strawberry shortcake in May, June and July.’

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