The full form of SOF IEO is the International English Olympiad.
SOF IEO is a prestigious annual competition for high school students from around the world who are interested in English and its applications. Participants compete in a series of challenging problems that test their English language grammar and comprehension skills. The competition aims to test the proficiency of the students in terms of grammar, vocabulary and language skills.
Schools in India, Bangladesh, Bhutan & Nepal have to pay SOF a registration fee of INR 125 and for other countries, it is USD 9 (including GST) per student / Olympiad towards the cost of the examination.