had better是一个
英语词组，意思是“最好”。
基本特点
1、其后接不带to的不定式，表示现在或将来的概念，如：
You had better sit here and have a rest. 你最好在此坐坐休息一会儿。（现在时态）
He had better stay in bed tomorrow. 他最好明天卧床休息。（将来时态）。
2、当其后接 have 加过去分词时，表示过去概念，如：
He had better have stayed in bed as I suggested. 他最好接纳我的意见卧床休息。（但他没卧床休息）
You had better have had tea,but you asked for a cup ofcoffee. 你最好喝茶，但却你要了咖啡。
3、had better 的否定式是在其后加not，如：
You had better not say it again. 你最好不要再提那件事了。
She had better not tell lies any more. 她最好再也别撒谎了。
4. had better 的疑问句是把had提前
The doctor had better see him.
Had the doctor better see him?
Who had the doctor better see?
He had better have had fewer exercises, hadn't he?
用法
有时后接动词的进行式，表示最好马上做某事;也可接完成式动词，表示最好做完某事或本该做某事而未做某事：
I think I’d better be going.我想我最好还是马上走。
You’d better be getting your clothes ready. 你最好马上把衣服准备好。
You had better have done that. 你最好把那事做完。
You had better have stayed here. 你本来应该呆在这儿的。
用法说明
(1) had better 用于提出建议或请求时，并不是一个很客气委婉的表达，它暗示对方有义务去做某事，因此通常用于长辈对晚辈或上级对下级等，而不宜反过来用。
(2) had best与had better用法和含义均差不多，但不如had better普通：
You had best get home before midnight.你最好在午夜之前回到家里。
We had best be going.我们最好现在就走。
(3) 有时可省略其中的had：
You better stop arguing.你们最好不要争论了。
Better not wait for him. 最好不要等他了。
Better say yes, if they ask you. 如果他们问你，你最好说“是”。
(4) 有时为了强调，可将better置于had之前：