You can learn how to speak English like an American just by practicing. Some people lose their original accent within the first year of speaking the new language. English is not difficult to learn and once you learn it, you can then practice pronunciation until you get it right.
LEARN ENGLISH - Learn the English language first before trying to be an expert at pronunciation. The English language can be difficult at first but it will become easier over time. If you can take a formal class it is very helpful. It is also helpful to watch movies and television programs in English. American soap operas are best because they tend to speak slowly and over dramatize each action, making it easier to understand what is happening and keep up with the story.
RELAX - Relax and go slowly at first. If you are nervous or worried about the way you sound, it will be more difficult to learn to speak English. Just relax and take your time. Do your best without worrying if people can understand you.
PRACTICE WITH FRIENDS - Find friends to practice speaking English. It is best if they are Americans if you are trying to learn an American accent. Practice role playing members of society, such as a teacher and student or a shopkeeper and a customer. Practicing real life scenarios will help you in your every day life.
If you are unable to find a friend to practice with, you can always speak to people in public. Speak to people on the subway, at restaurants, at school, at the store. If you try, everyone will help you. If you stay quiet, no one will know that you need help.
TOTAL IMMERSION - Move to an area where you are surrounded by English speaking people. Learning to pronounce English words correctly requires that you speak it continuously and regularly throughout your day. If you are working, going to school, visiting the doctor, shopping and being entertained in English, you will learn to speak it like an American. It may be intimidating at first, but you will find that you can catch on quickly. Try to make small talk whenever possible. People are friendly and will be glad to help you along whenever they can. Smile when you speak.
If you need additional help, look in the Resource section below. You can learn how to speak English like an American.