When to you use "che" and "di" for comparison?
I learned from Pimsleur that you use "che" and "di" to mean "than" for comparison, depending on the objects used for comparison. It seems to say that when the number is used, "di" is used; but for all others, "che" should be used.
e.g. La benzina costa meno di 2 euro. (The gas costs less than 2 euros).
e.g. Si guida piu' velocemente in Italia che negli Stati Uniti.
But another book has the following sentence:
Perche' l'appartamento di Antonio e' piu' grande dell'appartamento di Christine?
Why isn't this "e' piu' grande che l'appartament..."? Please explain in English as my Italian is not so good.