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 characters, incidents, and dialogues are products of the author's imagination and are not to be construed as real.

SOLUTION: Plural

PROBLEM: My teacher shifted uncomfortably.

SOLUTION: Singular

PROBLEM: This theory would only be plausible if all six assumptions were proven true.

SOLUTION:
Singular