How does language work?
Have you ever thought about how you acquired your mother tongue? You didn't do grammar exercises or memorize vocabulary lists. You didn't translate texts or read textbooks. You learned your native language through one single element: input. Yes, the big secret to acquiring English is understanding and harnessing the 'input/output principle'. Language schools and English classes try to bypass this principle, and that's why they fail. But winners make the best of the input/output principle, and that's why they succeed in achieving English fluency. It's as simple as that.
Your mind is pretty much like a computer's hard drive. You can retrieve data from it only if you have put the data into it beforehand. If you purchase a computer with an empty hard drive, it won't be able to produce any output, and it's the same with learning a language. The average learner doesn't understand the input/output principle and usually ignores the importance of the first step – the input.
You acquired your mother tongue because of one single fact: you received a sufficient amount of language input. It was all around you every day – your parents spoke it, your relatives and neighbors spoke it, it was on TV and in movies. You even began to figure out that those little black marks in your children's books were words, too. That's why you didn't have to learn grammar rules or vocabulary lists – your mind and senses were exposed to your native tongue long enough for you to start producing the correct output: fluent natural language.
English language schools try to sell you on the illusion that you can learn English without getting the necessary amounts of input. They tell you that their methods will 'teach you English', but the fact is that although some methods might seem like shortcuts, they can't replace the most vital component – natural language input. If you really want to become a winner, you need to surround yourself with English daily. In essence, you need to create an English language environment around yourself. Remember that if you attend an English class, your exposure to authentic English is very limited, or you may get no authentic input at all.
So, how do we define 'authentic English language input'? As you probably know, English is a 'non-phonetic' language. Many English words are written differently than they are spoken. That's why it is vital that you hear an English word or phrase several times before you see it. If you do it the other way round – that is, if you see the word before you know how it's pronounced – you will either forget the word entirely, or create your own imagined pronunciation of the word...which will probably be wrong! For example, let's take the words 'site' and 'opposite'. Both contain the same sequence of letters, s-i-t-e, but the words are pronounced differently. How would you know that, though, if you simply saw the words without hearing them spoken by a native speaker?
Before you can speak English correctly, you must listen to authentic English until you reach a level at which you know what 'sounds' correct and what doesn't. How can you speak English if you don't know what sounds right? You'll only know what sounds correct if you listen to real English. It's as simple as that.