Actually, English is the most speaken language in the world after Chinesse, which has more speakers because one of four persons in the planet is from China. The reasons of the importance of English, nowadays, are often related with American culture: there are a lot of movies, books, videogames, restaurants, shops... from Uncle Sam, which globalizes the world worrying a lot of people. ''Will English be the only language on the world one day?''. It is the crux of the matter which questions of everyone should learn English or not.
Well, Spanish and French are important languages too. But if you travel to another country, it is more probable that people understand better if you speak in English. For example, one morning I was coming to my high school when a French couple who was doing St James' Way asked me where the next town was. We couldn't understand in Spanish or French, but in English it was very easy. You haven't to go out of your country to meet English-speakers. If you go to a holiday place like Torrevieja, Benidorm or Barcelona, the workers in the hotels and restaurants will speak to you in English before than in Spanish. Also, it is interesting to make English or American friends. Watching movies and series in V.O. /original version) is more entertaining because sometimes the dub is bad. And listen to English music without subtitles is more enjoyable.
On the one hand, English is helpful and advisable. But on the other hand, it's difficult for most people because of the different way in which it is written and pronounced. So, a lot of students fail English at school and go to private classes. Furthermore, they also fail with extras! Most of the people don't like other languages because they want to work in this country and they think it isn't necessary. Fools!
In conclussion, I know English can be hard to learn for many people. But even if you want to work in Spain you must know a bit. Everyone should know a bit of English, because is the easiest language and helps for learning others. If schools devoted more hours for that subject, ther will be easier to learn. If people were interested more in it, learning would be easier. So, I suggest watching English shows and movie and game reviewers like Doug Walker (Nostalgia Critic) and James Rolfe (The Angry Video Game Nerd). I have learnt a lot of English with those two.