1. Вопросительное:
Are there two reference books on the shelf?
Отрицательное:
There aren't two reference books in the shelf.
2. Вопросительное:
Is there a lot of discussion about language learning now?
Отрицательное:
There isn't a lot of discussion about language learning now.
3. Вопросительное:
Is there a set of grammar exercises in this textbook?
Отрицательное:
There isn't a set of grammar exercises in this textbook.
4. Вопросительное:
Are there any courses for beginners at the University?
Отрицательное:
There aren't any courses for beginners at the University.
Употребили any, так как это вопросительное и отрицательное предложения, там some поставить нельзя
5. Вопросительное:
Are there any booklets here?
Отрицательное:
There aren't any booklets here.
По той же причине any.
6. Вопросительное:
Is there any sense in what he proposes?
Отрицательное:
There isn't any sense in what he proposes.