The main reason: It's fun!
Then...
It's a "global language";
English is the most useful language in the world;
Many books, technology, sports, pop music, advertising,...have the English as the dominant language;
Universal language in the Internet is English;
You can travel to an English speaking country or other without the need of a translator;
In the competitive job-market, it is necessary to speak English;
English is one of the easiest languages to learn;
At last but not the least...
...you will find your own reasons every time you use it!
Test your reading Comprehension and Reasoning...
English Riddles
1 - What part of the body has the most rhythm?
2 - What odd number becomes even when beheaded?
3 - What lives on its own substance and dies when it devours itself?
4 - "The beginning of eternity
The end of time and space
The beginning of every end,
And the end of every place."
http://www.world-english.org/riddles.htm
Ana Paula F