The key to English globalisation and extension up to the current is basically due to the three eras which English had undergone in the past. According to Svartvik and Leech(2006):
English benefited from three overlapping eras of world history. The first era was the imperial expansion of European powers which spread the use of English as well as of other languages, like Spanish, French and Portuguese around the world. The second is the era of technological revolution, beginning with the industrial revolution in which the English-speaking nations of Britain and United States took a leading part, and the later electronic revolution, led above all by the USA. The third is the era of globalization. (p.227)
The mentioned three eras are pertinent to one another, for example the second era namely the electronic revolution has introduced the Internet technology including e-mail, e-commerce, e-business and other e-activities which supports the third era, the globalisation era likely to take place
(Svartvik and Leech, 2006). Further development of the globalisation era leads to the commonness of English in several fields such as science, technology and world trade. Scientists
References: Anderman, G. And Rogers, M. (Eds.). (2005). In and Out of English: for better, for worse. Buffalo: Multilingual Matters, 2005. Axtell, R.E. (Ed.). (1995). Do’s and taboos of using English around the world. New York: Wiley Crystal, D. (a). (2003). English as a Global Language, 2nd edn. Cambridge: Cambridge University Press. Crystal, D. (b). (2003). The Cambridge Encyclopaedia of the English Language, 2nd edn. Cambridge: Cambridge University Press. Graddol, D. (1999) The Decline of the Native Speaker. In D. Graddol and U. Meinhof(Eds.). (1999). English In a Changing World. Great Britain: English Company Svartvik, J. And Leech, G. (Eds.).(2006). English One Tongue, Many Voices. Great Britain: Palgrave Macmillan.