Illiterates of South India definitely know 3 letters in English Language. They are able to identify the 3 letters from other letters and can understand what it is and who it is. The letters are g, m and r. Say MGR.
Few years back I went to a movie and my favourite movie, “உலகம் சுற்றும் வாலிபன்” in English “World Trotting Youth”, it was produced and directed by MGR. The title rolls on over Flower background and when the screen illuminated with Tamil words “இயக்குநர் எம்.ஜி.ஆர்” there was pin drop silence. Frames changes to English “Direction MGR” there were roaring whistle and applause.
M, G and R letters added like Adenine-Thyamine, Cytosine-Guanine in the DNA of the Tamils. It is inseparable and entwined.