For those who don’t know the rules — and I don’t blame you! — a semicolon does what it says on the box. Isn’t that nice? It’s a period on top of a comma, and it works like both a period and a comma. You can use it to separate two independent clauses — two sentences that work on their own — or to separate items in a series that would be particularly unwieldy with only commas, often because the items contain commas. (“Today I ate three desserts: a tiny cookie, which was free with my espresso; a bigger cookie, which was unfortunately a little dry; and a milkshake, which maybe took things too far.”)

LAUREN OYLER