In 1993, John Kim immigrated to the United States from South Korea at the age of 41. Although he had learned some English grammar in middle school, high school, and college, he felt that he needed to study English grammar again when he came to the United States. After restudying English grammar for eleven years, one day he decided to write an English grammar book for frustrated learners. He thought it would take two or three years, but writing an English grammar book has not been that easy. It has taken twelve years to finish this book.