What do you think is the best way to learn a language?

Formerly, knowing an international language for all people and countries of the planet was dispensable as the world was not so globalized and means of transport were are not so developed. Now, knowing   this language is very important to communicate with everybody, looking for a job or study, even in your own country.
Firstly, the communication would be easier if we all spoke the same international language. The schools should teach English from an early age, the same level as the Catalan and Spanish, and even give it more importance.
Secondly, English fosters relationships between people around the world as it is the international language. Wherever you go you will speak English thanks to the massive arrival of tourists in Spain, so you will have to use this language from time to time.
In my view, the English language is becoming more important but I think the Spanish education system should change the way to teach it, focusing on oral expression more than theory.