Question

Read the sentence.

Alma plans to visit London and Paris, where her parents went on their first trip together as a married couple.

What best describes the underlined part of the sentence, and why?

It is a restrictive relative clause because it begins with a relative pronoun, has both a subject and a verb, and is not necessary to the meaning of the sentence.
It is a nonrestrictive relative clause because it begins with a relative pronoun, has both a subject and a verb, and is necessary to the meaning of the sentence.
It is a restrictive relative clause because it begins with a relative pronoun, has both a subject and a verb, and is necessary to the meaning of the sentence.
It is a nonrestrictive relative clause because it begins with a relative pronoun, has both a subject and a verb, and is not necessary to the meaning of the sentence.

Answer 1

It’s the last option. It’s a nonrestrictive relative clause: it begins with the relative word "where," contains a subject and verb ("her parents went"), is set off by a comma, and adds extra (nonessential) information — you can remove it and still have a complete sentence.