In 1978, Jon S. Vincent, then Associate Professor and Associate Chairman of the Department of Spanish and Portuguese at the University of Kansas, published his critical survey (in English): João Guimarães Rosa . In his preface he writes: “It is no doubt excessive to preface a critical study with the admonition that readers of the study take the time to learn another language before proceeding further, but I know of few writers more worthy of that effort than Guimarães Rosa.” I can affirm: it’s worth it. A year or so ago I set out to learn Portuguese in an effort to more closely approach Grande Sertão: Veredas. I understand that even among Lusophones an approximate reading is, in many cases, the most a first-time reader of Grande Sertão: Veredas can ask for, so I don’t worry that I’m too (too) far behind.
Besides being able to read GS: V (relatively speaking), I can also now take advantage of the abundance of literature by and about the author available in Brazilian Portuguese. For example, this:
In 1983, Vilma Guimarães Rosa, João Guimarães Rosa’s daughter, an author in her own right, published Relembramentos: João Guimarães Rosa, meu pai  (Remembrances: João Guimarães Rosa, My Father), which includes an interview she gave to Brazilian writer and journalist, Suzi Frankel Sperber. The following is one question and response from that interview, translated by myself.
[Keep in mind that João Guimarães Rosa spoke six languages and read in fourteen.]