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: Her aura went muddy again and I watched her take a deep breath.

SOLUTION: Singular

PROBLEM: The ambassador was an ally and friend, who owed his post in Washington, D.C. to the Owl's influence and discreet lobbying.

SOLUTION: Singular

PROBLEM: The referee stepped between them and ordered Valeria to go to a neutral corner.

SOLUTION:
Singular