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:
Unseen to him, their pursuers followed.
answer:
Plural

question:
The deep boom of the two shots, which had been batting to and fro among the mountains, died away.
answer:
Singular

question:
The mattress is unused, so it should be quite comfortable. "
answer:
Plural