Usage of "as to..."

[milton.roger]

Dear instructors and fellow students,

One SC question I got wrong from MG CAT that involved the usage of "as to..." really had me puzzled over the usage of the phrase in question. I saw sentence such as "Scientists speculate as to why dinosaurs failed to survive the impact while some other reptiles thrived...." and it's considered perfectly ok. However in MG CAT, the usage of "as to" in a sentence which goes as " somebody debates AS TO whether XXX caused xxx..." is considered "REDUNDANT AND AWKWARD".

Can anybody give me some clues AS TO the rules of usage of "AS TO" please? Thanks in advance!

[tim]

No, we won't give you rules about how to use "as to", because it is almost always used idiomatically, which means you just need to learn to recognize when it is used properly and when it is not. The one piece of advice I will give you though is NEVER to trust an answer key that says something is wrong because it is "redundant and awkward". There is almost always a better reason for eliminating that choice, and you need to find it. Of course, this means you should NEVER use "redundant and awkward" as a reason to get rid of an answer choice on the actual test unless you're totally guessing..