1. There is a book beneath the box.
2. There is a book under the box.
------------------------------------------
Which one is correct? Do we have to use 'beneath' or 'under'? On the floor, there is a box. Between the box and the floor, there is a book. In this case, which preposition do we have to use?
In both cases, beneath and under both work, but speaking in terms of which sounds better, under would be a better choice as it would make the sentence flow better. However, which one you choose to use is entirely up to you. Just use the word that sounds better to you :) // under and beneath mean the same thing. For your sentence, "On the floor, there is a box. Between the box and the floor, there is a book." I'd recommend removing "Between the box and the floor, there is a book" since this is a confusing sentence. To rephrase your sentence: "On the floor there is a box. There is a book under the box."
Yui is right. Both those prepositions are fine.
Both "beneath" and "under" can be used to convey the same idea, but there is a subtle difference in their usage.
If you want to emphasize that the book is directly below the box, touching or in very close proximity to it, then "under" is more commonly used. So, in your first sentence, "There is a book beneath the box," the word "beneath" could be replaced with "under" without changing the meaning significantly.
On the other hand, if you want to imply that the book is located at a lower level but not necessarily directly underneath the box or in close contact with it, then "beneath" is a more appropriate choice. In your second sentence, "There is a book under the box," the word "under" suggests a more general location without specifying the distance or exact position.
In summary, if the book is positioned very close to the box, "under" is commonly used. If the book is at a lower level relative to the box but not necessarily directly underneath it, "beneath" is usually preferred. Therefore, based on your description of the book being located between the box and the floor, "beneath" would be the more appropriate preposition to use.