Поставьте эти предложения в отрицательную форму There is a bookshelf by the window

Question

Поставьте эти предложения в отрицательную форму There is a bookshelf by the window

Answer 1

There is not a bookshelf by the window.
если сокращенно то, isn't

Answer 2

There is not a bookshelf by the window