Would you be kind enough to share with me your opinion concerning the following two sentences?
She has eaten all the tart.
She has eaten the whole tart.
Thank you for your efforts.
I would use "all" for something that wasn't countable.
You have eaten all the rice?
He drank all the milk.
For a tart, I would say "the whole tart."
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.