I'm doing the exercises on Hewings' book: Advanced Grammar in Use and came across this problem that I have. Anyway, first, let me quote the explanation in the book.
Before singular countable nouns we usually use the whole rather than all the:
- They weren't able to stay for the whole concert. (rather than ... for all the concert.)
There are two questions that make me think and re-read this explanation:
Underline the more appropriate answer. If both are possible, underline both.
The new heating system makes (all the building / the whole building) warmer.
(All the room / The whole room) was full of books.
The key answer gives me: both are possible for number six, but the answer for number seven is only "the whole room". As explained in the example above that I can use either of them (although the whole is preferable), why all the room is incorrect? The book should have added the option if it were correct. I have looked up and both building and room are singular countable nouns if it matters.