Today we discuss appositives. An appositive is a noun, noun phrase, or series of nouns that identifies the same person, place, or thing by a different name. Whether to use commas with an appositive depends on whether it is restrictive or nonrestrictive, which is a question of meaning. Compare the following examples:
- My sister Lori went to the football game with me last weekend.
- Stephen’s car, a ‘65 red convertible Mustang, is the envy of his friends.
In the first example, the absence of commas indicates that “Lori” is restrictive (or necessary), because the author has more than one sister; so “Lori” identifies which sister is being referred to. In the second example, the author has only one car; so the commas indicate that “a ‘65 red convertible Mustang” adds only additional, parenthetical information.
Finally, although an appositive usually follows the word it explains or identifies, it may also precede it, e.g.:
The first state to ratify the U. S. Constitution, Delaware is home to Dogfish Head Craft Brewery.