The development of the English language falls into three reasonably distinct periods. Old English lasted from about A.D. 450, when the first Germanic tribes began to settle in England, until about 1100. Middle English extended from about 1100 to about 1475. And Modern English began about 1475 and has lasted to the present time. Of course the breaks were not as sudden and definite as these dates indicate. There has never been a year when the language was not changing, or a time when it was spoken with anything like complete uniformity. Nevertheless, the traits of the three periods are so different that a man who knows both Old and Modern English well will find a great deal of difficulty reading some of the Middle English writings without additional study in the important aspects of the language.

Q. What method of organizing details does the author use?