How to Memorize Vocabulary PART #1

http://www.italki.com/entry/528357

How to Memorize Vocabulary PART #2

http://www.italki.com/entry/528359

How to Memorize Vocabulary PART #3

http://www.italki.com/entry/528363

Firstly they read about particular subject,related their knowledge and study secondly they dont need to learn entire vocabulary they just use word to complete their discussion 

By reading and listening to good sources of English

There are native English speakers with poor vocabularies and native English speakers with rich vocabularies. The ones with the good vocabularies are those who read widely on a range of different topics, written in a variety of styles by a range of different writers.  

Speaking only for myself, I read; and when I come upon a word I don't know, I look it up in a dictionary.