"as good as" 和 "as well as" 都是用来比较两个事物或者描述某个事物的优点或能力，可译为“与...一样好”，其中“good” 为形容词，“well”为副词。
然而，它们在用法和意义上有一些区别，具体如下：
1. "as good as" 用于比较两个事物在某个方面的优劣，表示两者几乎是一样好，
例如：
- This new phone is as good as the old one.
- The new restaurant is as good as the old one.
2. "as well as" 表示某个事物除了已经提到的事物之外还有其他事物，例如：
- She speaks French as well as Spanish.
- He is good at math as well as science.
注意：此结构有强调的重点是第一个词（如French, math）, 根据例句可以体会这点。
扩展：
A as well as B 结构
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。
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。
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。
总结来说，"as good as" 表示两个事物在某个方面的相等或相似，而 "as well as" 表示某个事物除了某个方面还具有其他方面的能力或特点。