Are there any discounts or is there any discount?

English as a Second Language English Vocabulary, Grammar and Idioms
1

Hi guys, may i know which one is grammatically correct?

Is there any discount for this book?
or
Are there any discounts for this book?
and
what is the reason behind it?
Thanks!

2

Both are possible, though usually only one discount is applicable at a time, so the first would generally be more appropriate.

The only difference is that of singular/plural.