english is a worldwide language.your native language is helpful in your country only & when you have to communicate in other country you have to learn native language of that country or either communicate in english

[we must can speak english.] we must be able to speak English. my answer is : because of the USA is the only super power in this world, who speak English. in the Roman time, we must be able to speak Latin.

Generally (in my opinion), because the world is getting smaller thanks to the various information technology, being able to speak and understand English is essential in any business with global plans. But it does depend on which country you are in. For me being in Malaysia and having worked in a number of international MNCs, English is important as it is used as a common language for communicating with the various departments spread over the globe.