had better和would rather各是什么意思？

had better +动词原形 表示“最好。。。”
would rather + 动词原形表示“更想。。。，宁愿。。。”

You had better go to see him at once.你最好立刻去见他。
You'd better not stay here.你最好别呆在这儿。

I would rather stay here alone.我想一个人呆在这儿。
I'd rather die than live without you.
没有你我宁愿去死。

had better：最好
would rather：宁愿

最好 更愿意

前者是最好干某事，后者是宁愿干某事而不原干现在这件事