A brief history of the English Language

The "Three Circles" of English
Linguist Braj Kachru developed the three circles model in the mid-1980s to describe the spread of English and describe the various degrees to which English is prevalent in each country. The model visualizes English as a series of three differently-sized circles, arranged concentrically like a bulls-eye. While even Kachru admits there are still a few edge cases that don't fit cleanly into any of the three circles, his model nonetheless accommodates the majority of the world's countries using a mere three distinct categories:

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  The Inner Circle — The smallest circle, this section includes countries in which English is the native language of the majority of the population: mainly the United States, the United Kingdom and Ireland, Australia and New Zealand, South Africa, and much of Canada. The Inner Circle is the "norm-providing" circle, where native speakers continue to evolve the language's rules and usage.
  
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  The Outer Circle — This confusingly named circle is actually the second of the three, lodged firmly in between its smaller and larger siblings. The Outer Circle comprises countries with small communities of native English speakers and widespread use of English as a second language. English is not the primary language or the mother tongue, but it is widely used as a lingua franca language for trade and business, as well as a bridge language between people whose native tongues are different from one another. Countries in the Outer Circle include India, Nigeria, the Philippines, Bangladesh, Kenya, Jamaica and Papua New Guinea, and Singapore—where English is so prevalent that it may soon become the primary language. The Outer Circle is also referred to as the "norm-developing" circle, as it adopts but also challenges the norms created by the Inner Circle.
  
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  The Expanding Circle — The largest circle of all is the Expanding Circle, which encompasses countries in which English has no historic or cultural role and is neither a primary nor a bridge language—yet is commonly spoken as a foreign language, typically for business. Countries in the Expanding Circle include Russia, China, Japan, Brazil, and much of the rest of the world. The Expanding Circle is often called the "norm-dependent" circle because it relies upon the other circles to determine the proper usage of the language.