Are you learning on your own?
My advice is to practice it as much as you can.
1. If you have a teacher, maybe you can meet him or her after school to practice.
2. Watch movies or tv shows that are spoken in English. You can get them through cable or rent them at your local video store; if you have problems understanding, then press the subtitles bottom.
3. You can also get read-along books with CD or cassette;the stories are for children but it will help you develop your reading and pronunciation.
4. Search for chat rooms for ESL students. Get a friend and chat.
You can learn if you are determined to do so.