Regarding Masayuki Aihara's Oct. 29 letter, "Texts stand some in good stead": While the basics of proper English, or any language, rarely change, idioms and casual language change much faster. For example, when I was growing up in California, we would commonly refer to each other as "dude." Few people still use this word. I can think of dozens of other words and expressions that have dropped from common usage, to be replaced by others.
I am quite sure this is also true in Japanese, as evidenced by stories from The Japan Times itself about how young people talk in a version of casual Japanese that their parents can barely understand at times.
I commend Aihara for his determination in learning good English from textbooks and other similar materials. I would merely wish to caution him that there is a vast difference between textbook English and casual English.