关于as to 与 as for 有什么区别，网上有不少介绍，但感觉都没完全讲了解。
请英语答疑网的专家老师帮忙剖析和概要一下，万分感谢。
1. 用于句首的 as for 与 as to 意义非常相近，它们都能引出一个与前一个话题稍微有的不一样的话题。但 as for 在语体上不如 as to 正式，并且着重话题的转换，也就是说，它所引导的是前面尚未提到过的新的事情，因此，它不可以用于文章的开头。
We had a delightful weekend in the country. As for the traffic, we had no difficulty.在乡下大家度过了一个愉快的周末。至于交通，大家没遇见任何困难。
Much pasture land is under water; and as for the grain, most of that has been ruined. 大多数牧场都进了水，至于谷物，则大多数都被冲毁了。
As to the journey, we must decide about that later.关于旅游，大家需要将来再作决定。
As to that, I haven’t decided yet. 关于那件事，我尚未做出决定。
2. as to 常常与 wh-疑问词引导的动词不定式和名词从句连用（有时可省略），而 as for 却没此种使用方法：
Nobody could decide what to do. 哪个也不可以决定该干什么。
He’s very uncertain as to whether it’s the right job for him. 关于他到底适不适合做这项工作，他实在拿不准。
The numbers are a hint as to how to decipher the rest of the message.这类数字是破译其他信息的线索。（《达.芬奇密码》）
（摘自赵振才编著的《英语容易见到问题解答大词典》增订版第四版）
