It’s time that someone stood up for the semi-colon: the most majestic punctuation mark of them all. You may be thinking “But no one understands the semi-colon! Is it a comma? Is it a colon? Nobody knows!”
Worry not. Like the supremely functional spork, the ingenious combination of the spoon and the fork, the semi-colon functions as a half-breed spawn of the colon and the comma.
Now when a colon loves a comma very, very much…no, no. We won’t go there; you get my point.
“But when is the proper time to use a semi-colon?” you might ask. Well, I’ll tell you. When you find yourself with two related independent clauses, feel free to employ a semi-colon to combine them.
For instance, consider the following two sentences: Semi-colons are dangerous and scary. They make little children cry. Because both of these clauses can function as sentences apart from each other and they are related to each other through the same subject matter, they can cleanly be combined: “semi-colons are dangerous and scary; they make little children cry.”
While you still have two short independent statements, they are now disguised as a suave compound sentence.
It is a little-known fact about the semi-colon that while the subject matter must be consistent, the two independent clauses do not need to continue in the same thought.
Allow me to demonstrate this idea. Jonnie loves to sprinkle his research papers and journal entries with all sorts of obscure punctuation marks; Emily does not. In this case, the subject matter is not the subject of the main sentence, Jonnie. Rather, the subject is, all sorts of obscure punctuation.
So, instead of the second branch of the sentence being something like, he thinks they are some sort of intellectual symbol, it was free to go off and hook up with the different subject, Emily.
While the semi-colon is a fun-loving, free-wheeling sort of punctuation mark, it is not to be abused. If it realizes that you have wielded its powers to combine two non-cohesive sentences (known as a non sequitur, or an irrelevant piece of information), it will turn its mighty authority against you.
A silly, but obvious example of a non-sequitur would be something to the effect of Playing Twister in the dark never turns out well; red paint goes quite nicely with pale blue furnishings. If caught red-penned, you will be mocked by your friends and colleagues for your foolish semi-colon conduct; the half-breed punctuation will have its revenge.
Treat it well though, casually slide it into an appropriate position, and the semi-colon will earn its users great respect and admiration.