would do well to 是怎样的一种语气？

You would do well to remember that you are just a servant.

would do well to do sth. 可以看作是一个习语，意为“最好做某事”，表示给对方提出建议，意思跟had better do sth.相当。

例如：

You would do well to remember who is paying the bill.  你最好记住是谁付的帐。

You would do well to discuss the matter with him. 你还是与他商量一下这件事为好。

You would do well to say nothing more. 你最好不要再说了。

You would do well to take your doctor's advice. 接受医生的建议会很快好起来的。

You would do well to learn from him. 你最好还是向他学习。

You would do well to write more distinctly. 你要是再写得清楚一点就好了。

You would do well to consult him on the subject. 有关这个问题你最好还是向他请教。

I really think you would do well to take the blue one. 我确实认为你还是买那个蓝色的好。

You would do well to finish your homework this evening. 你最好今天晚上就完成了作业。

【深层分析】

1. 英语的would经常用来表示客气、婉转或请求，例如：Would you make me a cup of coffee?

2. 从结构上看，不定式还可以理解为条件：“如果做某事”，would do well表示结果。意思分解为：“如果你做到某事的话，那么你就做得漂亮。”例如，以下这两个句子就带有这种意思：

You would do well to take your doctor's advice. 接受医生的建议会很快好起来的。

You would do well to write more distinctly. 你要是再写得清楚一点就好了。