Dear WangGang
I have receive your letter,I know you want to learn English well.Maybe I can give some suggestions for you.
Firstly,you should listen to the teacher carefully ,take notes during the lecture.
secondly,speaking English as much as possible.
Thirdly,reading book about English widely and learn more phrases by heart。
Lastly,practise writing words.Insist on reading every day in the morning.
I wish it can do some help for you.