Many students tell me that they want to learn English quickly, and how can I teach them quickly?

Unfortunately, I cannot answer that question easily because how quickly someone learns a language depends on many factors, not just what they learn in school.

It depends on how similar your native language is to the language you're trying to learn. If your native language is Spanish, you can learn English relatively quickly. If your native language is Chinese, it will take you longer to learn English.
It depends on your age. Younger people learn new languages more quickly than older people. Experts usually say that it is best to learn a new language before you are 12 years old, but don't worry; you can still learn a new language if you are over 12 years old. It will probably just take you a little longer to learn.
It depends on how willing you are to take risks. If you aren't afraid to talk and perhaps make some mistakes, you will probably learn English faster than someone who is so afraid of making mistakes that s/he never talks.
It depends on how much you listen to English every day, and how much you speak English every day. If you only speak English during English class, and then speak your native language the rest of the day, you will not learn English quickly. In order to learn English quickly, you have to use it all day long, every day, for many months. You need to listen to English-speaking radio, English-speaking TV and movies, and English-speaking music. The more you listen to English, the faster you will learn it.
It depends on how much you read. The more you read English, the faster you will learn English.
It depends on how much you study English. If you only study English one to five hours a week, you will not learn English very fast. You should study English at least four hours a day, every day of the week, if you want to learn English fast.

Let me give you an example. I once taught a group of Venezuelan students who wanted to go to college in the United States. They came to my ESL course with no English at all, and after one year they were ready to attend college.

One year to go from zero English to the university is very, very good. They learned quickly because:

they spoke Spanish, which is very similar to English
they were young
they were not afraid to make mistakes
they paid attention during English class, and practiced using every new word and grammatical construction immediately
they were living in the U.S., on a college campus, and took every opportunity every day to speak English with American college students, to watch American TV and movies, and listen to American radio
they studied English four hours a day, five days a week, for one year

So if you want to learn English quickly, pay attention to these Venezuelan students and do the same thing they did. Then you can learn English quickly too.

Joan Pougiales, Ph.D. has taught English as a Second Language for over 30 years to college-bound students in the U.S., as well as to adult immigrants and refugees. Her web site is devoted to helping refugees and immigrants, beginning and intermediate students, to learn English and succeed in their new lives in the U.S. Visit her at http://www.growenglish.com