This sentence appeared in a reported speech exercise assigned to me.
"Are there any oranges in the fridge?", she asked her mom.
This is the exercise's key — it changed "any" to "some" when the above sentence is changed into reported speech:
She asked her mom if there were some oranges in the fridge.
Is this correct? I have never heard of the changing "any" to "some" rule when learning about reported speeches before, nor have I ever heard it when listening to British and American speakers. I feel like it's way more natural to say:
She asked her mom if there were any oranges in the fridge.
Is preserving "any" when changing to reported speech grammatical? I couldn't find any reliable information in dictionaries and other forums. Any and all help is greatly appreciated! Thanks in advance!