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
nonrestrictive clause

Answer 1

I'm guessing "formed by years of erosion" is the underlined part?

in that case, notice how it doesn't have a subject + predicate, making it a phrase rather than a clause

now, to decide between restrictive, consider whether it can be removed w/o fundamentally changing the meaning of the sentence or not