Commas here, commas there, commas everywhere — except when they’re nowhere to be found, leaving a wake of confusion by their absence. Many writers liberally use commas to insert pauses that are pleasing to the ear into their texts — no less a writer than Margaret Atwood has admitted to using commas this way. But comma use is more structured than that: it is based on grouping clauses and phrases together in a way that provides clarity for the reader. In this morning’s National Post (I know, I know — you’d think I never read anything else!), I spied a radio station ad that lacked clarity because a comma was missing:
Really Conservatives? A Justin attack ad with a clip from the last century?
There’s a comma missing, which leads the reader to think, after reading the first question, that what is being asked is whether or not the group being addressed is in fact made up of Conservatives rather than, say, Liberals or some other political group. The addition of a comma makes a difference:
This question is clear: the Conservatives are being asked, really?
Another interesting use of the comma is when the title of a work includes alternative titles:
The Subversive Copy Editor: Advice from Chicago (or, How to Negotiate Good Relationships with Your Writers, Your Colleagues, and Yourself)
The above is the title of a well-known book in the editing trade, and its punctuation is correct, of course. The comma after or makes clear that what follows is an alternative title. Without the comma, or could be mistaken for part of the title. Likewise, I think the following classic film title would have been better with a comma:
Dr. Strangelove or: How I Learned to Stop Worrying and Love the Bomb
The colon after or isn’t impeding clarity but it isn’t contributing to clarity, either. And the use here of the colon is not exactly “by the book,” although I for one am not a pedant about these things. But if I were editing the title, for the sake of correctness, I would omit the colon and use a comma.