Although a rather marginal phenomenon in Indo-European languages, in most other language families reduplication plays an important role in the organization of morphology. The repetition of (some part of) a word or stem or affix frequently expresses plurality, distributivity, intensity, a verbal aspect and aktionsart, but also diminution, attenuation, or others. This volume collects a series of articles which in a fertile discussion go beyond the limits of single theories and offer treatments of the most different aspects from formal and functional perspectives, semantics, morphology, and phonology, in different fields of linguistics (sign language, language acquisition, comparative studies), as well as original studies of a wide range of languages from different parts of the world.