B3: Subject-Verb Agreement, Separation of Subject & Verb: If a word, phrase, or clause separates the subject and verb of a sentence, the subject and verb must still agree. See Writing for Success Section 2.2 p. 59 or RULE 1 at the following: https://webapps.towson.edu/ows/sub-verb.htm
When a word separates:
My friend Elizabeth does not return my calls.
Limes, however, make the drink more acidic.
When a phrase separates (Remember the subject will never be part of a prepositional phrase):
One of Edna’s kids is going to be a doctor.
The training of tigers to jump through hoops has been a risky hobby.
When a clause separates:
Edna, who is one of the founding members of the club, hates croutons.
The teams that go the finals and win the trophy get free pizza for a month.
Be sure subject-verb agreement happen in all clauses:
Although the driveway with the oil stains looks nasty, the cars that make all of that mess are extremely beautiful, and people, regardless of their personal taste, admire them.