Why do we have to know English language?
Without English the world will come to its end. Huh, a little bit sarcasm, yeah?
English plays very important part in our life. If we are going to another country, we can talk there on English language or on its national language. There is a small chance that you know the national language of that country, but what would you do, if you don't know it? Only English.
With English you can go to every country and talk there as long as you want. Cool, isn't it?
Вот, небольшое сочинение. Можно развить тему дальше, я лишь помогла вам с началом.