What are the fundamental mechanisms governing the origin, evolution, and structural development of human language? Otto Jespersen, a renowned Danish linguist, provides a comprehensive examination of linguistic history, drawing upon extensive comparative data from various language families. He argues that language is a dynamic, living entity that evolves through the interplay of psychological needs and social interactions, rather than a static system of rigid rules.

Experts frequently cite this work as a foundational text in historical linguistics and philology. Readers often note the academic density of the prose, which reflects the rigorous scholarship characteristic of early 20th-century linguistic inquiry.