as for sb, as to sb, for sb, to sb 有什么不同

请教老师，as for sb； as to sb； for sb； to sb 有什么不同？

谢谢老师！

as for 和as to，意思十分接近，都含有“关于；至于；就...而论；对...而言”之意。它们有什么区别，主如果在句中的地方不同。as for 一般放在句首，而as to 则极少放在句首。

for 重在“目的关系”；to 重在“对象关系”。

1. As for me, I don’t mind what you decide to do. 至于我，我不在乎你们决订做什么。

2. No agreement was reached as to how much we should pay. 关于大家应对什么价格，没达到协议。

3. This medicine is good for you. 这药对你有好处。

4. This old man is good to us. 这位老人待大家非常不错。