An appositive is a noun phrase that explains or rephrases another noun phrase. It usually comes after the noun which it rephrases. It may also come before the subject of a sentence.
Buffalo Bill, a famous frontiersman, operated his own Wild West Show.
(appositive following a noun)
A famous frontiersman, Buffalo Bill operated his own Wild West Show.
(appositive before the subject)
Appositives are actually reduced adjective clauses. However, unlike adjective clauses, they do not contain a marker or a verb.
Oak, which is one of the most durable hardwoods, is often used to make furniture. (adjective clause)
Oak, one of the most durable hardwoods, is often used to make furniture. (appositive)
Appositives are usually separated from the rest of the sentence by commas, but some short appositives (usually names) are not.
Economist Paul Samuelson won a Nobel Prize in 1970.
In Structure items, all or part of an appositive phrase may be missing. In addition, the noun that the appositive refers to or other parts of the main clause may be missing.
∇ Sample Item
The National Road, ________________ of the first highways in North America, connected the East Coast to the Ohio Valley.
(A) which one
(B) it was one
(C) one
(D) was one
Choice (A) is incorrect; there is no verb in the relative clause. Choice (B) has no connecting word to join the clause to the rest of the sentence. Choice (D) is incorrect because a verb cannot be used in an appositive phrase. Note: which was one would also be a correct answer. Therefore, the answer is (C).