had better用法详解：
1.”had better最好、应该” 
had better + V原 
= 'd better + V原
否定形式：
had better not do sth. 
= 'd better not do sth.
最好不要做某事

1)had better可用于给出建议
You had better get ready for the competition.
= You'd better get ready for the competition.
你最好为比赛做好准备。
You had better go to bed early.
你最好早点睡觉。
You had better not play games tonight.
你今晚最好不要玩游戏。
You had better not take his dictionary.
你最好不要拿他的字典。


2)陈述应当做的或需要做的事情
He had better go home.
他该回家了。
I'd better start cooking.
我该煮饭了。

以上就是had better用法。同时须搞懂的知识：
should的用法