Deleting Commas Between a Modifier and What It Modifies

Commas between adjectives separate one describing word from the next: 'a long, narrow gallery' needs a comma after 'long' because both words modify 'gallery' equally. But the last adjective before the noun never gets a comma after it, because nothing separates a modifier from the thing it modifies. Write 'long, narrow, gallery' and that second comma tells the reader 'narrow' and 'gallery' are two separate items, which is false. The same rule covers prepositional phrases. 'Letters from the years the poet spent abroad' names which letters; the phrase 'from the years...' is glued to 'letters' and a comma before it would sever that link for no reason.

To check a sentence, isolate each comma and ask what two things it claims to divide. A comma has exactly one honest job: marking off two independent clauses joined by a conjunction, setting off an interrupter with a matching partner, separating items in a list, or following an introductory phrase. If a comma does none of these, and instead sits between a modifier and its target, delete it. Test every comma in a sentence on its own; one comma earlier in the sentence might be correct while the very next one is the error, as in 'After a delay of ten days, the survey crew, mapped the ridge,' where the first comma rightly follows the introductory phrase and the second wrongly splits subject from verb.

This skill sits next to recognizing interrupters, which need commas on both sides, not one. The habit of isolating each comma and naming its job is the same habit that catches a lone comma jammed between subject and verb elsewhere in the punctuation unit.