Rose is taller than I.
针对I来提问就是:
a. Who is Rose taller than?
Rose is taller than me. 针对me来提问就是:
b. Than whom is Rose taller than?
说白了就是把than理解成连词和介词后造成的问题。
从使用频率看Who is Rose taller than?尽管也很少见,但是要占绝对优势,没找到Than whom is Rose taller than?这样的例句,可能正如剑桥语法认为的,很正式的文体中才会出现Than位于句首。这个问题一直都是争议很大,比较分歧,见怪不怪了。但是需要说明的是,类似以下than的这种介词用法,人们普遍认为能接受:
c. They appointed Jones, than whom no one could have been less suitable.
d. He chose Kim, than whom no one could be more suitable.
e. It was decided by Judge Darwin, than whom no one could be more impartial.
f. Here is Captain Morse than whom there is no braver soldier. (Quirk第368页)
这个棘手的问题说说我的看法:
1. Fred eats more hambuegers than salads.
2. Sam likes bagels more than loaves.
我个人也觉得第1句不能改为What does Fred eat more hambuegers than?这不关than提不提至句首的问题,提到句首也不行。我的观察是第一句其中的比较是汉堡包和沙拉,这两样东西怎样比较多少?不如把这句理解成Quasi-coordinative类型更合适。那就没法改成问句了。我猜那本书的作者可能是这么认为的。
这样的话,因为第2句与第1句类型不同(体会体会为啥不同),可以用what 提问。