commas between subjects, verbs, objects, and complements
Commas that wrongly separate a subject from its verb, a verb from its object, or a verb from its complement.
A lone comma never separates a subject from its verb, even when the subject is long: in The tenants who signed the petition won their case, no comma precedes the verb won. Nor does one separate a verb from its object: in The survey found that most residents favored the plan, no comma follows found. Nor does one separate a verb from its complement: in The real problem is the deadline, no comma follows is.
A parenthetical element between these parts takes a comma on each side; the pair sets off the interruption, not one part from another: The committee, after a long debate, approved the budget.
Two exceptions are standard. A comma follows a verb of speaking when a direct quotation is its object: She said, “The doors open at eight.” A comma also separates a subject from its verb when the same word ends one and begins the other: Whoever wins, wins.
See also parenthetical elements: when to use commas; commas with quoted speech; compound predicates: comma use; comma.
Examples
UseThe players, by a wide margin, rejected the offer. (Paired commas enclose a parenthetical element.)
AvoidEveryone who attended the meeting, received a copy. (A lone comma wrongly separates the subject from its verb, received. Write Everyone who attended the meeting received a copy.)
AvoidThe report showed, that sales had doubled. (A lone comma wrongly separates the verb showed from its object, the clause that sales had doubled. Write The report showed that sales had doubled.)
AvoidHer goal is, to finish by May. (A lone comma wrongly separates the verb is from its complement. Write Her goal is to finish by May.)