All you can do is practise, I9 had the same problem learn Bengali. I was frustrated, I found it difficult to speak with any Native or Advanced speaker. It took me more than 8 months to become a advance speaker. But I had to work extremely hard, I found several Bangladeshi pen pals, I paid for private tutoring, I found some people in my town who speak the language and practised with them, I read endless texts books, I started watching Bangladeshi programmes on TV. It was really difficult but I did it at the end and it felt great. So as my friend above said... Practise is the key, there is no fast way of learning English, the more time you put in to it... the more you will learn. Hope this helps.

practise bu sometimes we dont find apropriate words and we use wrond words but also we dont reailze it ... how can we overcome this challenge?

Practice, practice, practice.

1. Go to native English speaking countries. 2. Make some native English speaking friends in your country. One of them is best choice I think.