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: A heavy gloom fell over Reuben.

SOLUTION: Singular

PROBLEM: " Dogs can be a nuisance. "

SOLUTION: Plural

PROBLEM: Not long after that, partial paralysis began to set in, and Zachariah became disabled before he had learned to walk.

SOLUTION:
Singular