这一对形容词的涵义并不相同。
Same是“同一的”、“一样的”、“没有变的”;similar是“相像的”、“类似的”。因此，the same mistake 是“同样的错误”，a similar mistake是“类似的错误”;on the same plan是“以同一的方法”，on a similar plan是“以类似的方法”。
另一点要注意的是，same之前要用the、this或that 等词，只有在口语里例外。similar之后用to，不用with。same的名词是sameness;similar的名词是similarity。
请看下面例句：
I'm in the same class with him.
我和他在同一个班里读书。
The patient is much the same as yesterday.
病人的情况和昨日大致一样。
You can pay now or later; it's all the same to me.
你现在付也好，以后付也好，对我来说都一样。
有时候，same和this、that、these、those等词连用，可以表示嘲笑、侮蔑等意。例：
What is the use of this (that) same patience?
如此忍耐又有何用?
下面是similar的例子：
The cat and the tiger have similar features.
猫同虎有类似的特点。
A cat is similar to a tiger in many ways.
猫同虎有很多地方相像。
Gold is similar in colour to brass.
黄金和黄铜的颜色很相像。
A high-level delegation has arrived for talks apparently aimed at trying to revive a similar relationship that has waned in recent years.
一个高层代表团到来会谈，显然想改善近年采已衰退的关系，恢复类似以前的关系。