To learn English, because English is used worldwide as a global language in communication. Whether it is the country where if we or they are visiting foreigners, uses.
To learn English because the world is used. English as the medium of communication. Whether it is a country where if we or they are foreign to it will use.
To learn English, because the world is used. English as a lingua franca in communication. No matter which country if we or he is a foreigner to travel will use.