Now, I'm very tired about the english grammar. because would....
i'm studying grammar about would But it is really difficult to me. how is difficult... I have read
many times grammar book, dictionary and some lessons from internet But I dont understand
exactly.. It is still cant understand. Some grammars are that I have already been understood. just like this..

I would like - this is polite way to say " I want "

ex)I would like some coffee
I would like to know about english more.

Would you? - this is polite way to say to requests

ex) Would you open the door please?

Would you like to? - this is polite way to say to offers

ex) Would you like some coffee?
Would you like to see movie with me?

These is all that i have been understood. But some forms(many forms) are still difficult to me.
I know would is used in various sitautions. But How could i know that situations? I cant definitely tell and write any sentences with any certainly about Would.
Please help me about that. I would like to know How is would used in What situations.
or tell me some easy and good lessons about grammar Would That I can see from internet.

Thank you sir
You're right that "would" is complicated.

Your examples of polite usage are correct. Sadly there are no easy rules, so your question is too general to be answered in a forum like this. You need a good textbook.

I will tell you one thing: "Would" is the past tense form of "will".

But as you already know, that's not its only use.

Thank you sir.
I will read my grammar books and lessons from internet continually. I think i will understand that If i will read english sentences and grammar books often. thank you sir for your help!