appositives: comma use
Comma use with an appositive, a noun or noun phrase that identifies or describes the same person or thing as another noun or pronoun.
Set off an appositive with commas when it adds information about someone or something already identified: Rina, our project coordinator, approved the schedule. The phrase our project coordinator adds information about Rina, who is already identified by name. This is a nonrestrictive appositive.
An appositive that identifies which person or thing is meant takes no commas: My colleague Rina approved the schedule. Here, Rina identifies which colleague is meant. This is a restrictive appositive.
The distinction depends on meaning in context. Compare The committee’s chair, Daniel Ortiz, opened the meeting with Committee member Daniel Ortiz opened the meeting. In the first sentence, the committee’s chair identifies the person by a unique role, so the name is nonrestrictive and takes commas. In the second, the name is restrictive: it identifies which committee member opened the meeting, so it takes no commas.
A nonrestrictive appositive within a sentence takes a comma on each side: The annex, a former warehouse, now contains classrooms. At the end of a sentence, it takes only the opening comma: The classes meet in the annex, a former warehouse. An introductory appositive takes a comma after it: A former warehouse, the annex now contains classrooms.
A title or occupational label placed directly before a name takes no commas: Architect Lena Shah presented the drawings. When the description follows a name that already identifies the person, set it off: Lena Shah, the architect, presented the drawings.
See also comma; nonrestrictive clauses.
Examples
UseOur neighbor Felipe repaired the fence. (Felipe is a restrictive appositive: it identifies which neighbor is meant, so it takes no commas.)
UseThe youngest finalist, Ines Park, received a scholarship. (Ines Park is a nonrestrictive appositive, because the youngest finalist already identifies the person, so it takes commas.)
UseWe visited Bell House, a museum devoted to local history. (A museum devoted to local history is a nonrestrictive appositive, so a comma sets it off.)
UseAn experienced mediator, Jonah resolved the dispute. (An experienced mediator is an introductory appositive. It is nonrestrictive, because Jonah already identifies the person, so a comma follows it.)
AvoidThe main entrance, a narrow doorway beside the café leads to the courtyard. (The nonrestrictive appositive needs a closing comma after café.)
AvoidThe term, leaseholder, appears in the final paragraph. (Leaseholder is a restrictive appositive: it identifies which term is meant, so it takes no commas.)