Actually English speakers DO NOT use the structure "HAD BETTER" to refer to a past tense. The meaning IS present or future. However, I've studied British English. Ask people from America or Australia if they use it for the past too.

Yes, we say "I'd better go," all the time. But no "would better," is not correct and does not exist. You can say it "It would be better if I said I'd better go."

Hi Sunshine! We actually use this phrase to mean " to have to", or to give advice about the present or the future. For example: "It's raining - I'd better go inside." Or: "You'd better call your mum - she's worried about you." The formula is "had better" + infinitive verb (but without the "to"): "I had better go." Happy studying! Matt

"had better" can be used in present or future. We use this phrase to talk about actions that we think people should do ( The USA had better not elect a racist president) or what should happen in the moment (I'd better go otherwise I'll be late for my reservation). "had better" is used if something bad or negative will happen. "I'd better" is informal. You can use "I should." "Would better" is not used, perhaps "you'd better" which would be understood as "you have better."

Love this question by the way. I'd never thought about "had better" and why/when we use this until I saw your posr yesterday. Definitely a strange term when I look at it through the eyes of a non native!