"There are many books in the library."

Translation: Ci sono molti libri in biblioteca.

[h0w412d]

Why not "nella biblioteca"? Is this like "in cucina" where the article can be omitted?

[mukkapazza]

You can also write 'nella biblioteca' but you're right :) The article isn't necessary here. A few other examples: sono in cucina, siamo in chiesa, andiamo in campagna...

[BillofKempsey]

But only sometimes?

If so, is there a rule which applies?

[il_filippo]

What is more common language? Nella or in?

[Winnie461621]

Why does the hint say "nella" but the right answer,"in"?

[norill1]

when can i say "vi sono" instead of "ci sono"?

[frank379644]

Here is my take on the two options: in/nella.When you use "nella",you literally mean you are in that place such as a church .
With "in" you again mean the same but with the underlying sense that the place embodies/represents/epitomises some intangible qualities .So for chiesa[church] this could represent a sense of peace & holiness & for cucina[kitchen] this might suggest a feeling of creativity .
Of course I could be wrong & I would then seem like a pseud. Let me know what you think.