Thank you... I really appreciate your comments.

The spoken language vs. what is considered grammatically correct is an interesting discussion... almost incredibly endless but fantastic!!!

Su.Ki., SHL and Tempus, you have a great amount of valious information to contribute to the learners. Thank you, thank you, thank you for being here!

Thanks for the corrections too :)

Thank you to all of you for your explanations

I can say, in short, that "had better" is correct grammatically, and expresses advice/suggestion for a specific situation which needs to be done.

There are other speaking, daily or "natural" uses:

-  "It would better that italki users give more context to many of their questions."  by John´s example. This example provides advice and it´s supposed to be: 

It had better that Italki users give more context...

-  "You better  listen to Julie or you will get hit by a car" by Brian. It should be: 

You had better listen to Julie or...

- "It would be better if guns turned to roses...". It includes be so, it´s not an advisable action.

it refers to the modal would

........

I tried to understand the origin of "would better" which is easier for me now.

Thank you again for the complete information all of you gave for this question

Starting a lesson

In concluding, English is easier because of its high degree of exposure in the world, and because the majority of its speakers have been involved with the language since they were kids. They have forgotten how hard was to learn.

I can tell you one reason more of English is easier. As many Spanish learners of 

English know, English doesn´t require verb conjugation when using simple past , past participle, continuous future, etc., as we do in Spanish. Besides, there are more verbal tenses in Spanish than in English, and there are no different male/female adjective as we (spanish speakers) have. 

I actually don´t know others languages,  only these points are enough for me to say English is easier.