我想个别句子可以改正一下。
Dear sir,
I want to ask you an improtant question. Can you give me some advice? Although I can read some English books and speak simple oral English, Sometimes I think that my English is a little poor, because I don't know more about it .I can't talk to others as well as write a long messages and listen in,such as BBC and so on. My english is at a freshmen's level, I want to improve it, but I have no idea about how and what to do, so I wrote the letter to you to ask the good way to improve my English .
I'm looking forward to hearing from you.
yours sincerely
Camille