There are two main areas that have to be worked on : vocabulary, and grammar. A good way to improve your English is by often to watch English movies in which people are speaking properly.The first way is to widen your vocabulary. Reading is important in learning new words, as is looking up words you don’t know in a dictionary so that you will be able to use them yourself. Make sure that you're fully understand the meaning because it is no good using new words if you don’t use them in the correct place. The final thing to really work on is grammar, and spelling and punctuation with it. Reading will help a great deal in this aspect, as you can learn from seeing it used properly.