If you work with words, you’re probably familiar with the related but supposedly antithetical concepts known as prescriptivism and descriptivism. And people take sides. Either you’re a stickler (you’re a prescriptivist) or you go with the flow (you’re a descriptivist).
We learn from CMOS 6.23 that “a comma is not normally used to separate a two-part compound predicate joined by a coordinating conjunction.” In other words, when the subject isn’t repeated after a word like “and” or “but” in a compound sentence, a comma is usually omitted.
According to The Chicago Manual of Style, commas and periods are almost always placed before a closing quotation mark, “like this,” rather than after, “like this”. This traditional style has persisted even though it’s no longer universally followed outside of the United States and isn’t entirely logical.
Few people will accept that up means down simply because you say so in writing, not even if you’re perfectly consistent about it. Still, when it comes to editorial principles, consistency is second only to being right.
There are a few simple conventions for presenting thoughts in fiction, and these overlap with the conventions for setting off dialogue and other quoted speech or text—or anything that might normally take quotation marks.
An en dash can function either as a strong hyphen or as an ordinary dash. As a strong hyphen, it can connect numbers or words. As an ordinary dash it’s nothing special.
It hasn’t reflected publishing standards since the Jazz Age. And it isn’t Chicago style. But some people continue to do it in their own documents—from manuscripts to emails. You’ll even see it occasionally on social media.
Switching to italics for the occasional word or phrase borrowed from another language—and not listed in a standard English-language dictionary—can be helpful to readers.
Its generic name is the serial (or series) comma, but a lot of people refer to it by a fancier name: Oxford comma.
Anyone who learned to type on a QWERTY keyboard would be excused for thinking the semicolon is the most important mark of punctuation in English; why else would it be sitting right there on the home row?