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.

A flat screen television fitted snugly into the upper left corner wall.
Singular

But at least his current efforts to make up for his mistakes were paying off.
Plural

A narrow stair, rough-hewn and cut from the stone of the mountain, led down beneath the keep.

Singular