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 off-duty homicide investigator put her napkin on the table, not realizing the impact of her words on the latecomers.

SOLUTION: Singular

PROBLEM: The front yard was several acres long.

SOLUTION: Singular

PROBLEM: A sob tore up Aly's throat, and she thrashed, struggling to break away.

SOLUTION:
Singular