Description: On the basis of analyzed examples from many languages, basic concepts of grammaticalization theory are explained. Grammaticalization is delimited against other types of variation and change. Degrees of grammaticalization are assessed by well-defined criteria and parameters. Many well-documented cases from different functional domains are analyzed in depth. Issues of directionality are settled on a theoretical basis. The cognitive bases of grammaticalization are identified.
Brief description: Christian Lehmann is professor emeritus of the University of Erfurt, Germany. His publications deal mainly with the grammar of different languages, with general comparative grammar, specifically with grammaticalization, including Thoughts on grammaticalization (3rd ed. 2015).