A Hundred and One Rules in Arabic Grammar!

  1. Interrogative Particles أ / هل   (revisited). =================================================

The Arabic language does not tolerate the use of  هل  with any form of ليسَ  in order to make a question. You have to stick with أ

**أليسَ الطالبُ في المکتبةِ؟**

Isn't the student (m) in the library?