1. 用于本义，两者意为“与……一样好”，但 good 是形容词，而 well 是副词。如：
他说英语说得跟她一样好。
正：He speaks English as well as her.
正：His English is as good as hers.
2. 用于引申义，两者的意思很不相同：
(1) as good as 意为“几乎”“差不多”(=almost)。如：
He as good as said I’m a liar. 他无异于说我撒谎。
We’re as good as ruined. 我们差不多完蛋了。
习语be as good as one’s word意思是“说话算数”。如：
You’ll find that she’s as good as her word. 你能了解到她这个人很讲信用。
(2) as well as 表示“而且”。如：
She’s clever as well as beautiful. 她不但漂亮，而且聪明。
He speaks Spanish as well as English and French. 他不仅会说英语和法语，而且会说西班牙语。
该结构强调的重点是在前面一个词（体会以上例句的译文）。如：
A as well as B=not only B but also A
该结构连接两个成分作主语时，其后谓语通常与前面一个主语保持一致。如：
Mary as well as her friends is going to Paris. 玛丽和她的朋友要去巴黎。
与动词连用，动词通常要用动名词。如：
As well as breaking his leg, he hurt his arm. 他不但摔断了腿，而且还伤了胳膊。
He sings as well as playing the piano. 他不但会弹钢琴，而且会唱歌。
有时也可与主句动词的形式一致或用动词原形（但均不如用动名词常见）。如：
As well as eating [ate, eat] a seven-course meal, they drank three bottles of wine. 除吃了一顿有7道菜的饭之外，他们还喝了3瓶酒。