had better的用法详解
1. had better 的基本用法特点
其意为“最好”、“应该”，后接动词原形，与情态动词should用法相似，其中的had通常缩略为'd：
You'd better get some sleep.你最好去睡一会儿。
We had better go before it rains. 我们最好在下雨前就去。
2. had better 如何构成否定式和疑问式
构成否定式时，通常将not置于had better之后(而不是had之后);而构成疑问式时，则通常将had(而不是had better)置于主语之前：
I'd better not disturb him.我最好别去打扰他。
What had we better do? 我们最好怎么办?
【注】在否定疑问句或反意疑问句中可将not与had连用：
Hadn't we better go now? 我们是不是现在就去呢?
had better 在反意疑问句中,疑问部分一般用"had+主语?",但有时可用"will you?"表示一种请求或建议.如：
You'd better not go out today,had you?
今天你最好不要外出,好吗?
I must stay at home this afternoon.You had better come to my house,will you?
今天下午我必须留在家里,你最好来我家,好吗?
3. had better 后接进行式和完成式动词
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。
4. had better的几点用法说明
(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：
"I promise I'll pay you back." "You better had." “我保证还给你。”“你最好还给我。”
