Question

read the sentence.
the canyon, formed by years of erosion, was a breathtaking sight to behold.
what best describes the underlined part of this sentence?
○ restrictive phrase
○ nonrestrictive phrase
○ restrictive clause
○ relative clause

Explanation:

1. First, distinguish between phrases and clauses: a phrase has no subject - verb combination, while a clause does. The underlined part “formed by years of erosion” has no subject - verb (it is a participial phrase), so it is a phrase, eliminating “restrictive clause” and “relative clause”.
2. Then, distinguish between restrictive and non - restrictive: a restrictive phrase/clause is necessary to identify the noun, while a non - restrictive one provides extra information. The phrase “formed by years of erosion” gives extra information about the canyon (the canyon is already identified, and this phrase just adds details), and it is set off by commas (a sign of non - restrictive elements in some cases, and here it's a non - restrictive phrase as it's additional info). So it's a nonrestrictive phrase.

Answer:

B. nonrestrictive phrase