The volume presents a complex and multifaceted study on Chinese idiomatic expressions, in particular on chengyu. These are short expressions that condense into four characters the themes, lexicon and the style of philosophical, historiographical, poetic and narrative works belonging to Chinese literary tradition. Given their prestige and their frequency of use, chengyu play a role far from marginal for learners. The book proposes a critical review of existing literature on idiomatic expressions, their acquisition and their psycholinguistic processing, which is integrated with a vast and comprehensive review of the scientific literature on Chinese idioms. The study also proposes a linguistically-informed definition of the class of chengyu and describes its main characteristics. It discusses the difficulties encountered by learners, and offers suggestions to facilitate the understanding and memorization of this category of expressions, so as to increase teaching effectiveness.