Braj Kachru's original model of three concentric circles describes the English language's presence in a global context, simplifying the cultural and social identity of different nations based on their educational structure and historical relationship with British imperialism.

In its simplest form, the model describes the relationship like so. Countries in the "Inner Circle," like the United States, claim English as their first language. The "Outer Circle" is used to describe countries that speak English as a second language, such as India, due to Britain's former colonies there. The "Expanding Circle" includes countries that provide some way of learning English in a limited capacity to facilitate more cohesive interface with the rest of the world.

However, because of the breadth and scope of all of these relationships historically, it will be necessary for you to outline a few parameters to determine the depth with which you will to answer and justify each area of this line of inquiry. These parameters include but are not limited to the length of the assignment, the focus of the course and unit, the time period and regions you are most focused on, and the extent to which your reference materials provide this information.

For example, you could focus on the colonial aspects of our language through British mercantilism, the advent of technology to globalize access to countries within the "Expanding Circle," or the role English plays in determining class in various countries.

I would recommend defining the rhetorical context in which you will be writing about this topic, then using that as a guideline. You may simply be asked to give a brief overview of each of these concepts, but one could easily teach a course in any of the examples highlighted above.