you’d better后面直接加动词原形，也就是不带to的不定式，构成you had better do sth句型，意思是你最好做某事。实际上，had better do sth是固定搭配。
you'd better后面加什么形式
you'd better即you had better后面加动词原型 (即不带to的不定式)，构成you had better do sth.句型。意思是"你最好做某事”。
better英 [ˈbetə(r)] 美 [ˈbɛtɚ] ；adj.较好的;更合适的;能力更强的;好转的。
adv.更好地;更;更妥；v.胜过;上进；n.更好者;更有才智者。
第三人称单数： betters 复数： betters现在分词： bettering过去式： bettered .
过去分词： bettered.
had better do sth. 最好做某事。
这是固定搭配, 适用于各种人称和数。had可与主语缩写也可不缩写。
you'd better的双语例句
1、You'd better see a doctor about that cough.
你最好找医生治治你的咳嗽。
2、You'd better look sharp or you'll be late.
你得快点，不然就迟到了。
3、Maybe you'd better tell me what this is all about 。
也许你应该告诉我这究竟是怎么回事。
4、You'd better consider this and factor this into your decision making.
你最好考虑一下这一点，并在做决定时将其考虑在内。