There are lots of opportunities which are available if you know English language. First of all, you can go to an English-speaking country for a holiday(of course,if you can afford it). Secondly,you can have an English-speaking penfriend and write letters to him(it's affordable to anyone). Thirdly, as English is an international language,you can work in many foreighn companies and earn a lot of money. Also, knowing of English is nesessary in our everyday life because there are lots of products which are written in English.
As we can see, English language is nesessary nowadays.