Jens Otto Harry Jespersen or Otto Jespersen (July 16, 1860-April 30, 1943) was a Danish linguist who specialized in the grammar of the English language. He was born in Randers in northern Jutland and attended Copenhagen University, earning degrees in English, French, and Latin. He also studied linguistics at Oxford. Jespersen was a professor of English at Copenhagen University from 1893 to 1925. Wikipedia
The definitive Wikipedia entry for Otto Jespersen. Wikipedia is the biggest multilingual free-content encyclopedia on the Internet. en.wikipedia.org/wiki/Otto_Jespersen