instruction:
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.
question:
The courtyard is shaking so badly that for a second I'm not sure I haven't caused another earthquake.
answer:
Singular

question:
The dog promptly dropped to a sitting position, his tail still wagging furiously.
answer:
Singular

question:
" Four more contacts with the enemy, all of them with the wax spiders.
answer:
Plural