Punctuation Department · Today with The Mayor

Comma

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Comma

The Mayor teaches this column himself. Work through each capitalization job below, then take the quiz.

Separate the items in a series

A comma separates each item in a series of three or more, including the serial (Oxford) comma before the final and or or. The serial comma prevents a list from reading as if the last two items were one.

In a sentence

The report was clear , thorough , and fair.

Now you try

Three or more items in a row, each split by a comma, with one before the and. You could try snacks, school supplies, or pets.

Put the comma before the coordinating conjunction

A comma plus a FANBOYS conjunction joins two independent clauses. A comma alone is a comma splice; a true run-on uses no mark at all. For two closely linked independent clauses, a semicolon (Sheriff Semicolon's mark) is the stronger fix.

In a sentence

The storm knocked out the power , so we lit candles.

Now you try

Each side has to stand on its own. Like: I was tired, so I rested.

Set off the part you could lift out

A pair of commas sets off a nonrestrictive element, one that adds information the sentence does not need to make sense. A restrictive element, one the sentence needs to identify what it means, takes no commas.

In a sentence

The result , surprising as it was , held up under review.

Now you try

Drop in a who or which part: My bike, which is blue, is fast.

Set off the introduction before the main idea

A comma follows an introductory element (a word, a phrase, or a subordinate clause) before the main clause, so the reader sees where the introduction stops and the main clause begins.

In a sentence

Without a single wasted word , the speech landed.

Now you try

Start with Yes, First, or an After ... phrase: After lunch, we played.

Every comma does one job

A comma can also signal a pause or a slight break for style, but the pause follows the structure, not the other way around. A comma never joins two independent clauses by itself: that is a comma splice, and a semicolon or a FANBOYS word is the fix.

In a sentence

She paused , weighing the words.

The verdict , fair by any measure , stood.

Now you try

Series, join, set apart, or introductory. Every one of them separates.