请问Many students are watching TV与Many a student is watching TV有啥子区别?

题目

请问Many students are watching TV与Many a student is watching TV有啥子区别?
后者错在哪呢?

答案

many
adj.许多,多的
Not many people can write with the left hand.用左手写字的人并不多.
pron.许多
Many are called but few are chosen.要得多,选得少.
其本身就是要求复数形式