TASK DEFINITION: In this task you are given a sentence. You must judge whether subject of the main clause is singular or plural. Label the instances as "Singular" or "Plural" based on your judgment.
PROBLEM: The large mansions, which lined both sides of the street, bore stately and placid witness to their conversation.

SOLUTION: Plural

PROBLEM: Names, characters, businesses, places, events and incidents are either the products of the author's imagination or used in a fictitious manner.

SOLUTION: Plural

PROBLEM: ' Things haven't been so easy for me, mostly because of my own doing.

SOLUTION:
Plural