In most professions, you need to speak English - in business, computer technology, medicine, law, architecture and design, engineering, the media, science, teaching and in the military.
You must be proficient in English to register with professional organisations in the United Kingdom, the United States of America, Canada, Australia, New Zealand and South Africa.
You also need to prove you can speak English for citizenship in the USA, UK, Canada, Australia or New Zealand.
Most professions and all universities in the UK, USA, Canada, Australia and New Zealand ask you pass an English test. You must also pass a test to emigrate to those countries.
The tests include: IELTS (International English Language Test System). IELTS is used in the UK, Europe, Australia, New Zealand, Asia and Africa. TOEFL (Test of English as a Foreign Language) is used in the USA, Europe, Asia, Africa and South America. The Cambridge exams are the highest standard and include: CAE; CPE; Cambridge BEC:Preliminary; Cambridge BEC:Vantage; Cambridge BEC:Higher.
Some people learn English very fast, others take a little longer. How long you take to learn English depends on why you are studying - for a test? For a job or university interview? Or just for talking with your friends? Do you know some English already? How many hours can you study each week?
The answers to all of these questions are important - but the most important thing is to join the right school and to find a course that you enjoy.
Finally, to learn English super fast and well, you must work with a tutor who can help you to be the best.