Braj Kachru is a prominent linguist known for his work in the field of English language studies. He is best recognized for developing the concept of "World Englishes," which explores the various forms and uses of English around the globe. His research highlights how English adapts to different cultural contexts and how it serves as a global lingua franca. Kachru's model categorizes English into three circles: the Inner Circle, where English is the native language; the Outer Circle, where it is used as a second language; and the Expanding Circle, where it is learned as a foreign language. This framework helps to understand the diverse ways English is used worldwide.