Grammaticalization is a process of language change through which words representing objects and actions are transferred into grammatical markers. New function words are thus created by deriving them from content words, instead of from existing bound, inflectional constructions. Some concepts are grammaticalized, while others like evidentiality are not. A distinction between lexical items and grammatical items is integral to the understanding of the process of grammaticalization. Lexical items are content words which carry specific lexical meaning. Grammatical items are functional words with little or no lexical meaning which serve to express the grammatical relationships between different words. This book explores all the important aspects of grammaticalization in the present day scenario. It includes some of the vital pieces of work being conducted across the world, on various topics related to this process. This book is a vital tool for all researching or studying grammaticalization as it gives incredible insights into the cross- linguistic variation and universal tendencies.