The colon is a common cause of bellyache. The semicolon can leave people dazed and confused. But rather than cutting them completely from your punctuation diet, refer to the following guidelines and you’ll soon find just the right dosage for all your writing needs.
The colon
The colon is very useful for introducing things, for example:
* bullet points
* lists within your text, eg I learned three things from this article: how to use colons, how to use semicolons, and that the writer liked extended metaphors.
* long, indented quotes.
It can also act like an arrow, pointing the reader on from a statement to the reason for, or outcome of, that statement. For example: she was elated to know what those two little dots were for: she started using them with confidence and glee.
The system here always implies a link between the two sections, and can be generally summed up as:
* cause: effect, or
* fact: explanation.
In UK English, always use lower case after a colon. (American style guides usually recommend the opposite.) The only exception is if you are introducing bullet points that are each full sentences.
The semicolon
Think of the semicolon as the ‘super comma’: they act in a similar way, but indicate a longer pause. They can also be used to show a link between parallel ideas.
Use them to separate long phrases in a list when at least one of the phrases contains a comma, eg My favourite mediums for writing semicolons are: crayons; 2B pencils; fountain pens, in blue or black; and, obviously, huge magic markers.
Semicolons are also good for linking two related clauses. In this way, the semicolon replaces the word ‘and’ or ‘but’ eg I prefer the explanation about colons; Denise prefers the semicolon section.
So don’t be afraid: used fairly sparingly, these two punctuation marks can bring much more clarity and variety to your documents. Bon appétit.
If you have any more questions about how to use them, ask the experts on our forum by clicking here.
Tags: colons, how to use colons, how to use semicolons, semicolons
Join over 13,000 subscribers and get business-writing news and tips straight to your inbox. Fill in your email address below and we'll send you our 64-page book 
I love the clarity and the friendly tone of this explanation, but I wonder about that use of “eg.” Certainly it correctly introduces the example that follows; however, it seems inappropriately tacked on to the sentence before. My recommendation would have been for parentheses around the “eg” and example. Is this a difference between American and British English usage?
Thanks for your comment, Lester.
It may not be specifically a difference between American and English usage, but certainly it is a question of style.
Our style tends towards the minimalist with punctuation. With ‘eg’ or ‘ie’, we put a comma before it and nothing afterwards. Putting parentheses around every example – we do have quite a few! – might look a little cluttered. We also tend to reserve parentheses for optional information, whereas the examples are integral to the piece.
Ultimately, as is so often the case, it is a matter of preference.
[...] with pondering the placement of the much less familiar semi-colon or the enigmatic apostrophe, the ubiquitous comma might seem hardly worth worrying about. They’re [...]