unsane

There is a vast punctuation chasm that a lot of people fail to jump, and personally it drives me nuts. I know I’ll be accused of being a punctuation freak with what I’m about to say, but you can’t defend the indefensible, and for people who know and love language, you can’t just say “ignore it”. Ignoring it means putting up with imperfection, putting up with the punctuation equivalent of someone saying “beresk” instead of “berserk”.

It’s the difference between a colon and a semi-colon. These two punctuation symbols are not interchangeable. Or, in the words of Inigo Montoya from The Princess Bride:

I do not think it means what you think it means.

Let’s look at the definition of the two symbols. Starting first with a semi-colon and referring to the Wikipedia entry for it:

Semicolons are followed by a lower case letter, unless that letter is the first letter of a proper noun. They have no spaces before them, but one space after (possibly two in a monospace type). Applications of the semicolon in English include:

• Between closely-related independent clauses not conjoined with a coordinating conjunction:
  • “I went to the swimming pool; I was told it was closed for routine maintenance.”
  • “I told Ben he’s running for the hills; I wonder if he knew I was joking.”
  • “A man chooses; a slave obeys.”
• Between independent clauses linked with a transitional phrase or a conjunctive adverb:
  • “I like to eat fish; however, I don’t like to be eaten by them.”
  • “I like being odd; yet, I hate being different.”
• Between items in a series or listing containing internal punctuation, especially parenthetic commas, where the semicolons function as serial commas:
  • “She saw three men: Jamie, who came from New Zealand; John, the milkman’s son; and George, a gaunt kind of man.”
  • “Several fast food restaurants can be found in each of London, England; Paris, France; Dublin, Ireland; and Madrid, Spain.”
  • “Examples of familiar sequences are: one, two and three; a, b, and c; and first, second, and third.”

Note how we get a starting rule almost immediately, “Semicolons are followed by a lower case letter, unless the letter is the first letter of a proper noun”.

Now moving onto the colon, and the Wikipedia entry for it:

As with many other punctuation marks, the usage of colon varies among languages and, for a given language, among historical periods. As a rule, however, a colon informs the reader that what follows proves and explains, or simply provides elements of, what is referred to before.

As you can see, these two definitions are wildly different. There’s nothing in the semi-colon definition that suggests it can be used as a substitute for a colon, and nor is there anything in the colon definition that suggests it can be substituted for a semi-colon. Indeed, if we go back to one of the examples for a semi-colon, you’ll even see a combined use of the two symbols:

“She saw three men: Jamie, who came from New Zealand; John, the milkman’s son; and George, a gaunt kind of man.”

So the use of the colon in that identifies that there will be a list, or a series of elements to follow from the previous statement. “She saw three men”, “colon”, indicates that following the colon will be something to do with those three men. We then have three partial sentences, separated by semi-colons: “Jamie, who came from New Zealand; John, the milkman’s son; and George, a gaunt kind of man.”

Writing the above without colons and semi-colons, we’d get text resembling the following:

She saw three men. Jamie was from New Zealand. John was the milkman’s son, and George was a gaunt kind of man.

Here’s an example of the most common incorrect use of a semi-colon you’ll see. It is the only time I will willingly mis-use the semi-colon:

There are three things you need to consider;

• PCs are riddled with viruses
• PCs need frequent rebuilding
• Macs have neither of the above problems.

To someone who actually understands punctuation, the entire meaning of the above is lost through the incorrect use of the semi-colon. Or to put it another way, it’s like writing “(Hello ” to a LISP programmer who understands emoticons. In short, it’s a troubling error that drives people with a passion for language nuts – and it’s plain wrong.

So please, if you need to use a colon or a semi-colon, and you’re not sure which is which, check!