It all starts with you
The best tip is to get immersed in daily American life and practice, practice, practice. If you can isolate yourself off from everything but English for a period of time do so - this can be a real help. Read American newspapers and magazines, watch American television and films and listen to the radio. Interact with Americans as much as possible. Chat with neighbors, shop keepers, taxi drivers and bar attendants - anyone is a good target for getting a bit of practice in. The more you are exposed to English and the less you use your native language, the quicker you will learn. Memorizing grammar rules is wonderful but nothing beats practical experience.
Television is probably the quickest way to increase your level of listening comprehension. It's free and you are guaranteed to hear people speaking naturally (and fast). The more you listen and watch, the quicker you will find yourself picking up words and phrases. You will be surprised how much you can learn in a way that is relatively painless.
To get started many people take an English as a Second Language (ESL) course. Commercial language schools that offer courses can be found in the Yellow Pages under Language Schools or on the Internet. There may be an international cultural center in the area that offers language courses. There are also many towns and cities that offer free English language courses at the local City College, which are public colleges.
Note that the difference in price between various language courses is not always an indication of quality. When choosing a course, the number of teaching hours should be taken into account as well as the number of people per class. If you need to gain a basic knowledge of English in a short timeframe, there are intensive courses that will give you a kick-start in the language. Otherwise, it is generally advisable to learn at a more measured pace over a longer period of time. Another important aspect is the course location. Check if the course location is near the place you are staying and well-connected with buses or subway stations.
If you're struggling to find or choose a course that offers the best value, try subscribing to Expat Offers. The service will email you with alerts on the latest offers and deals available for language schools in your area.
If your time is limited or the idea of a language course doesn't appeal to you, you could take private one-to-one classes. Depending on the teacher, this is a very good way to learn. But be prepared to spend more money since this is also usually the most expensive way of learning English.
Most language schools can arrange private lessons, but it is usually much cheaper to contact a private teacher directly. Quality will vary depending on the ability and experience of the teacher. This can have a large impact on your progress, especially if you're a beginner. When choosing, make sure you feel comfortable with the person and the way they are teaching. If you feel you are not making progress with a teacher, don't be afraid to change.
Being an exchange student is a very popular way to learn English and experience the American culture. There are many companies that offer this service. Usually they work the same way and the process involves coming to the United States to study and live with an American family. This option can save you some money, and give you the opportunity to host a student from the U.S. in your country in the future.
If you're serious about learning the language, invest in a big edition of an American Dictionary of the English Language. This will give you the most updated and comprehensive information about modern English spoken in the United States. If just starting out, get yourself a pocket-sized bilingual dictionary with your own language and upgrade to a larger dictionary when you need to.
Did you know: The longest English word in popular usage is Antidisestablishmentarianism (a movement opposed to the separation of church and state) at 28 letters.