according to是介词，后接名词或代词；according as是连词，后接句子。但是对于“后接句子”的理解要注意：
▲according as是连词，后接句子——指的是后面直接跟句子，句子前面不能另有其他“引导词”（因为according as就是引导从句的连词）。如：
You may go or stay, according as you decide. 是去是留由你自己决定。
Everyone contributes according as he is able. 每个人根据自己的能力作出贡献。
You will be praised or blamed according as your work is good or bad. 你受表扬还是责备得看你的工作好坏决定。
▲according to是介词，后接名词或代词，正如其他介词也可后接名词性从句一样，介词according to也可后接名词性从句（此时的名词性从句必须要自己的“引导词”，如连接代词或连接副词）：
He is an honest businessman, according to what everyone says. 根据大家所说，他是位诚实的商人。（according to 后接what引导的宾语从句what everyone says）
The amount of tax people pay varies according to where they live. 居住地不同，人们所交的税额也各不相同。（according to 后接where引导的宾语从句where they live）
These apples have been graded according to how big they are. 这些苹果已经按照大小分了等级。（according to 后接how引导的宾语从句how big they are）
They were arranged according to when they happened. 它们是按发生的时间安排的。（according to 后接when引导的宾语从句when they happened）
▲联想其他介词后接宾语从句：
I’m surprised at how fast she can run. 我很惊奇她能跑那么快。（at后接how引导的宾语从句how fast she can run）
I haven’t the least interest in what he is doing. 我对他在干什么毫无兴趣。（in后接what引导的宾语从句what he is doing）
It depends on when he did it. 这取决于他什么时候干了此事。（on后接when引导的宾语从句when he did it）