Grammar for Everyone - Barbara Dykes 2007
Semicolons
Introduction
Part II The parts of speech
Margaret Fullerton, in ’Summer On The Lakes’ 1844, likened semicolons to the stops in a paragraph of thoughts about one’s life. This is probably a very good description, as semicolons provide a pause between connected thoughts and lie somewhere between commas and full stops. For the more mature writer, semicolons are very effective because they suggest a balance, but to avoid misuse and confusion, it is wise not to introduce semicolons too early.
Perhaps the best way to describe semicolons is to say that they link associated thoughts or statements.
For example:
The mantis rested on a green leaf; you might never notice it there.
He had no food; nor did he have any money.
Another use of semicolons, which is similar, separates thoughts set within lines of poetry while preserving the poetic flow.
For example:
I laid me down upon the shore
And dreamed a little space;
I heard the great waves break and roar;
The sun was on my face.
(from ’Pre-Existence’ by Francis Cornford)
Lynne Truss reminds us that only full sentences should be joined by semicolons - otherwise one may fall into the habit of running on with a kind of stream of consciousness sentence structure, in the manner of Virginia Woolf, which is not generally acceptable.