Get control of your commas

is arguably the most misunderstood of punctuation tools. ask someone about comma rules and even those who begin with confidence are likely to trail off apologetically. This is because comma use is not fully explained by rules; it depends in part on taste. But, as David Crystal insists in his history of punctuation, variation in comma use is neither infinite nor totally idiosyncratic [1]. It turns out that there are two broad schools of punctuation, and understanding them can help us to unravel the complexities of comma use. In the elocutional school, with its origins in antiquity, commas indicate intonation and pauses in oral speech. In the grammatical school, which arose with the advent of the printing press, commas express grammatical relations among parts of the sentence. What’s tricky is that both approaches are still alive and well, so that most of us have been trained, explicitly or implicitly, to use a bit of both in our writing. Getting control of your commas requires distinguishing between rules and preferences, which map closely onto the grammatical and elocutional schools of comma use. The aim of this Writer’s Craft section is to help you ascertain when commas are prohibited, when they are necessary, and when they are unnecessary but acceptable as a matter of preference.