Periphrasis straddles the border between two major linguistic components, morphology and syntax. It describes a situation where a grammatical meaning, such as a tense, which could be expected to be expressed morphologically within a word, is instead expressed by a syntactic phrase. Inclusion of syntactic phrases in morphological paradigms creates analytical and theoretical problems that have yet to be resolved by linguists, who have been hampered by the rather narrow range of data available for consideration and by a lack of adequate theoretical devices. This book addresses the challenge by broadening the range of phenomena under discussion and presenting new theoretical approaches to the problem of periphrasis. Part I takes four key languages from diverse families - Nakh-Daghestanian, Gunwinyguan (Australian), Uralic and Indo-European - as examples of languages in which periphrasis poses particular problems for current linguistic theories. Part II views periphrasis in different contexts, determining its place within the morphological and syntactic systems of the languages it is found in, its relations to other linguistic phenomena, and the typological variation represented by periphrastic constructions. Treating periphrasis as a morphological and syntactic phenomenon at the same time and applying the criteria worked out within the Canonical Typology approach allows linguists to view periphrasis as a family of phenomena within a typological space of syntactic constructions used to fulfil grammatical functions.