A modern English grammar on historical principles

Otto Jespersen, a pioneering Danish linguist, began work on A Modern English Grammar on Historical Principles in the early 20th century to move beyond traditional, prescriptive approaches to language. Rather than imposing rules on how English should be used, he sought to describe how it had evolved historically, drawing on an immense corpus of literary and non-literary sources to analyze the structure and syntax of the language as it was actually spoken and written over time.

The publication of the volumes by Allen & Unwin represented a significant shift in philological study. Jespersen's work was widely praised for its rigorous methodology and its emphasis on the fluidity of language, cementing his reputation as one of the most influential grammarians of his era. By focusing on the 'historical principles' behind current usage, he provided a framework that remains a foundational reference for students and scholars interested in the development of modern English.