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: Inside the box was a pencil -- a yellow, wooden pencil, with a graphite lead.

SOLUTION: Singular

PROBLEM: A mass of recruits had already gravitated to the Whites.

SOLUTION: Singular

PROBLEM: The real author behind it all is the Almighty, Who writes about all of us. "

SOLUTION:
Singular