What does an advertisement say about English learning?

An advertisement says "Learn English in six weeks, or your money back". Of course, it never happens quite like that. As we know, no language is easy to learn except one’s mother tongue. And think how much practice that gets. Before the Second World War people usually learn English in order to read English literature. Now most people want to speak English. Every year many millions of people start to learn English. How do they do it?
     Some people try at home, with books and tapes, some use radio or television programs, others go to school or attend evening classes. Nowadays people even may use the Internet or various computer softwares to study English. If they use English only two or three times a week, it will take a long time to learn it, like English learning at school. A few people try to learn English fast and study six or more hours a day. It is clearly easier to learn English in England, Canada, Australia or the United States. However, most people cannot afford this, and for many it is not necessary. They need English in order to do their work better. For example, most scientists and engineers chiefly need to be able to read books and reports in English. Whether English is learnt quickly or slowly, it is hard work. Good teachers, books and machines will help, but they cannot do the student’s work for him.