This article presents a review of works on expressive linguistic objects in the Principles and Parameters framework ( Chomsky 1995a , b ; 2001 ). It discusses case studies of expressives in Russian, German, Halkomelem, Maale, Walman (Valman), Kolyma Yukaghir, Itelmen, Tongan, and Spanish, as well as in Breton and Yiddish. The article demonstrates that two semantic types (size and attitude) of expressives correspond to a great variety of syntactic structures across languages, as well as within a single language (e.g., Russian). It shows that there is no direct one-to-one correlation between the form and function of expressives, which has important implications for the syntactic–semantic mapping of categorization ( Wiltschko 2008 , 2014 ). This review is of interest to theoretical linguists, language-area specialists, and language typologists. It is also relevant to the fields of education and endangered Aboriginal language documentation, maintenance, and revitalization, as one-third of languages investigated here are endangered and on the verge of extinction (e.g., Halkomelem, Itelmen, Kolyma Yukaghir, Walman).