Thank you for your advice ,mario and kinson. It is important to use english. Writing, speaking ,hearing！

What do you think in this free ebook? The Century Vocabulary Builder. http://www.amazon.com/The-Century-Vocabulary-Builder-ebook/dp/B000JMKWFC/ref=sr_1_1?ie=UTF8&qid=1339371612&sr=8-1

for example... you said "knack" i have never heard that before but i looked for it in web translator and figured out you mean "tip" which is more commonly used and now i know another word, just like that you learn more vocabulary, just try to translate everything you are thinking to english and if there is a word or part of your thought you dont know how to say it in english, go find out and you will learn a lot because what we are thinking we are most likely to need those words again.

first you learn grammar rules.. how to make phrases correctly in general... second you learn a lot of vocabulary and apply it to make new phrases everytime... those are the 2 big steps in learning english in my opinion.